Kessenju

Kessenju (決戦獣), formerly known as Kessenju! (決戦獣!) until 2008, and also known in the US as Kessenju!: Ultimate Battle Beasts, is a media franchise by ACS consisting of a trading card game, several manga and anime series, and several video games.

The Kessenju trading card game was developed and published by ACS, and was launched in November, 2000 in Japan and May, 2003 in North America. In North America, the Kessenju trading card game was distributed by Topps up until 2006, when it was discontinued due to dismal sales numbers. As of this writing, the North American version of the game is out of print, and the game is now only available in Asia, and only printed in Japanese.

Kessenju was later adapted into a manga series by Hideaki Terasaki, which was serialized in Shogakukan's CoroCoro Comic magazine, and ran from December, 2000 until April, 2005. It follows the story of a 12-year old boy named Sendo Tenryu, who aspires to be the best duelist there is. Since then, four sequel series have been made, each starring a new protagonist. An animated adaption of the first series, Kessenju!: Ultimate Battle Beasts, was later produced by Nippon Animation and ran from 2002 to 2005.

Gameplay
In Kessenju, players draw cards from their respective decks and take turns playing cards onto the field, with the main goal of the game being to use creature attacks and magical spells in order to attack each other until one of them wins. A game of Kessenju is typically played between two players. Before each match, both players would decide who gets to play first using a mutually agreeable method of decision: dice rolls, a coin toss, and rock, paper, scissors are among the most common.

Each player must use a Main Deck containing at least a minimum of 40 cards, up to a maximum of 60 cards, with a limit of up to 3 copies of the same card in a deck (barring several "restricted" cards, which only allow one copy for each deck), as well as a "Gem Deck", composed of 20 Gem cards. In addition, players may also adopt a "Side Deck" consisting of 15 cards that they can swap with some of their Main Deck cards in between matches, but this is completely optional.

When dealt with a bad hand at the start of the game, the player is given an opportunity to "mulligan" their starting hand, which allows players to shuffle an unsatisfactory opening hand back into the deck at the start of the game, draw a new hand with the same number of cards, and repeat until satisfied. To dissuade players from abusing this rule, their opponent may choose to draw one additional card for every mulligan performed.

Players starts the game with 2500 "Vitality Points" (VP), as well as five "Barrier" cards and an empty "Mana Pool", which is the main resource of the game. For every turn, during each player's Gem Phase, players have to draw the top card in their Gem Deck and place it automatically on their Mana pool, which constitutes to one mana point. Unlike in other card games that utilize mana, the Gems in Kessenju are placed in a separate deck that the player must draw from during each turn. This gives the game more flexibility against "mana screw" and/or "mana flood".

Putting mana into play requires tapping (done by rotating the card 90 degrees, indicating that it has been used that turn) a certain amount of Gems, including at least one mana from the same color, or realm, as with the card that the player uses. More powerful cards cost more mana, so as the game progresses, more Gems will be in play, more mana will be available, and the quantity and relative power of the Creatures, Spells and Equips played tends to increase.

Players begin the game by shuffling their decks and then drawing five cards. On each player's turn, following a set phase order, they draw a card from their Main Deck, draw a Gem from their Gem Deck and put it into play, tap their Gems as necessary to gain mana in order to summon creatures, cast spells and/or equips, engage their creatures in an attack round against their opponent and their creatures, who may use their other creatures or trigger their Barriers to block the attack, and then complete other actions with any remaining mana, before ending their turn. Tapped resources remain tapped until the start of the player's next turn, during what is known as the "Neutral Phase", so the player must also plan ahead for their opponent's turn. The standard order of phases in a turn goes: Draw Phase > Neutral Phase > Gem Phase > Main Phase 1 > Attack Phase > Main Phase 2 > End Phase.

During the Attack Phase, one-by-one, players target their opponent's creatures and engage in combat with them, during which the opponent can choose to assign a creature that hasn't been targetted by the player as a "blocker", and divert all damage to the target creature into the blocker instead. Alternatively, they can instead trigger one of their Barriers to summon a creature that can be used as an emergency blocker, or cast a Spell that counters their opponent's attack. After the Attack Phase, creatures who have attacked and aren't destroyed in the current turn are "tapped" until the players next Neutral Phase, and can't be used as a blocker for the opponent's turn. When there are no creatures in the opponent's field, the player can then use their creatures to deal direct damage to the opponent. In Kessenju, players cannot use their creatures to deal direct damage to their opponent until they have no more creatures in their field. Thus, players have to utilize their creatures and spells effectively in order to clear the opponent's field from their creatures and then damage their opponent's VP directly.

When attacking, players compare their creature' Attack (when attacking creature directly) or Defense points (when attacking a blocking creature), which usually comes in values around the hundreds. When the attacking creature has higher Attack points than the target creature, the target is destroyed, and vice versa, with any excess damage being dealt to the defending player's VP instead. This is what's known as "piercing damage". When both creatures have the same amount of Attack points, both are destroyed. Blocking creatures are unable to destroy opposing creatures, but are able to avert excess damage to the player's, even after being destroyed by a creature with greater Attack points. When the blocking creature has more Defense points than the opponent's attacking creature's Attack points, piercing damage is reflected to the attacker's VP instead. When both the attacker and blocker have the same amount of Attack and Defense points, respectively, none of the creatures are destroyed.

A typical Kessenju setup consists of the Main and Gem Decks, the playing field, where players can place their creatures and Spell cards, the mana pool, where Gems are placed and tapped for usage, and the Barrier zone, which consists of five face-down cards waiting to be triggered. When a player's Creature or Spell card is destroyed either through battle or after usage, they are sent into the "graveyard". Certain Spell cards allow players to steal cards to from the graveyard, and transfer them onto their own hand for their own use. Alternatively, certain creatures and Spell cards have effects that cause cards to be "expelled", removing them from play for the remainder of the game.

The game ends when:


 * One of the players' VP is reduced to zero. If both players reach zero VP at the same time, the game ends in a draw.
 * One of the players has to draw from an empty deck.
 * One of the players forefeits, automatically awarding a win for the opposing player.
 * The requirements of certain cards with special conditions which trigger automatic win or loss conditions, are filled.

Barrier System
One of Kessenju's distinguishing core mechanics is its Barrier system, where players can set up five cards from their Main Deck in advance and summon them in the middle of the match, allowing them to counter against their opponents' powerful creatures and spells.

At the start of the game each player possesses five "Barriers", which consists of five Creature or Spell cards of the player's choosing. During the opponent's Attack Phase, players can activate a Barrier Trigger, and use the card's effect to save themselves or their creatures from damage, at the price of skipping their next Gem Phase. Before triggering a Barrier, the player also needs at least one Gem in their mana pool with the same color as the cars used as a Barrier.

Several cards in the game hinge upon the Barrier mechanic. For example, certain creatures and Spell cards are able to destroy the opponent's Barriers, rendering them unable to use Barrier Trigger. Other Spell cards allow players to install aditional Barriers with cards from their hand, while others have the inverse effect, taking one of their own Barriers and putting them on their hand.

Summoning a Creature card through Barrier Trigger automatically assigns it as a blocker, shielding the player or a targetted creature from any potential damage. If the summoned creature remains on the field, the player may then use it as if it were summoned regularly. Summoning a Spell card through Barrier Trigger would activate the card's effect as if it were summoned from the hand.

Cards that can be used as Barriers are distingused by a "Barrier" logo on the bottom left of the card, as well as possessing the "Barrier" keyword ability in the case of creatures. Several cards, most notably Quick Spell cards, creatures with high Defense or "on summon" effects (which are activated as soon as the creature is summoned), benefit from being used as Barriers. There also exist several Spell cards that are specifically meant to be used as Barriers. This gives the game an added layer of strategy, giving the player flexibility regarding which Barrier cards to use for the duel, and when to trigger them.

Conversely, several cards cannot be used as Barriers due to either impracticality or potential as game-breakers. These include all Gem, Equip and Arena cards, most high-cost Spell cards (barring certain high-cost Quick Spell cards), all Evolved Creature cards, and any Creature card with a casting cost of 4 or more mana.

Card Types
The game features five types of cards: Gem, Creature, Spell, Equip or Arena, each with their own specifications and uses.

Gem Cards
Gem cards serve as the main source of mana throughout the whole game. Unlike other cards, gems are placed in the "Gem Deck" a 20-card deck that's separate from the main 40-card deck. Aesthetically, the Gems of Kessenju are based on the 12 birthstones and their variants, with only Jade and Amber being based on non-birthstone precious gems.

Gems are played once per turn, during the player's Gem Phase. Upon entering the Gem Phase, players have to draw the top card in their Gem Deck and place it automatically on their Mana pool. This is a mandatory phase per turn that is only skipped by negation spells from the opponent, or when the player performed a Barrier Trigger the turn prior.

Basic Gems only conjure mana of the realm they represent, while Dual Gems are able to give out mana from two realms, thought they may only be tapped for one mana color at a time. The Diamond Gem represents all five realms, and can be used as a proxy for the five basic Gems. Players may add any amount of Basic Gems in their Gem Deck, as long as it reaches the 20-card limit. Meanwhile, Dual Gems have a limit of three copies per deck, and Diamonds are restricted to one copy per deck.

There are spells that can alter how many Gems a player can draw and play per turn, as well as other spells that generate free mana for one turn without the need of an extra Gem. Gem cards cannot be used as Barriers.

Basic Gems

 * Topaz (Light)
 * Amethyst (Dark)
 * Sapphire (Water)
 * Ruby (Fire)
 * Emerald (Earth)

Dual Gems

 * Onyx (Light/Dark)
 * Tanzanite (Dark/Water)
 * Tourmaline (Water/Fire)
 * Bloodstone (Fire/Earth)
 * Jade (Earth/Light)
 * Lapislazuli (Light/Water)
 * Garnet (Dark/Fire)
 * Aquamarine (Water/Earth)
 * Amber (Fire/Light)
 * Alexandrite (Earth/Dark)

Special Gems

 * Diamond (Universal)

Creature Cards
Creature cards are summoned by each player to attack the opposing player's creatures or VP, or defend against the opponent's attacks. Each creature represents a certain race (Wyvern, White Mage, Dark Mage, Elf, etc.), and typically has a set amount of Attack and Defense points (usually a value between 100 and 2000), which are used to determine the results of battles, as well as certain "keyword" abilities that take advantage of their strengths in combat. By default, summoned creatures can only be used to attack on the turn after they are summoned, unless the creature has the "Rapid" keyword ability.

Certain Creature cards also have varying special effects, which tend to be unique with each creature. The rules text on the card specifies the creature's effect. Some creatures have effects that activate on summon (once they are put into play), on first strike (once they attack an opposing player's creature), or on death (once they are destroyed by an opposing player's creature or Spell), while others have more specific triggers for their abilities (i.e.: Ignel, the Flame Dragon gains +100/+100 for every Wyvern creature on the field).

Low cost (3 and below) creatures can be used as Barriers, where they can be summoned as a blocker in response to the opponent's attack, to shield the player from the attack or trigger an effect. Creatures that benefit from being used as Barriers the most include "Blockers" (Defense-centric creatures that can't attack, but possess high Defense) and creatures with "on summon" effects. Creatures with a mana cost of 4 and above cannot be used as Barriers.

Evolved Creatures are creatures which require a creature of the same race on the player's side of the field, after which the Evolved Creature is then summoned by placing it on top of that creature. Evolved Creatures tend to be stronger than regular creatures of the same mana cost, or possess powerful effects. Evolved creatures cannot be used as Barriers, regardless of mana cost.

Keywords
Most creatures have a set of keyword abilities, which take advantage of some of their strengths in order to gain the upper hand against the opponent. Most of these keyword abilities are endemic to certain realms. (e.g., "Terminate" is only available to Dark creatures)


 * Attentive - This creature untaps automatically during your End Phase.
 * Barrier - This creature can be summoned from a Barrier through Barrier Trigger.
 * Blocker - This creature can't attack.
 * Charger - When this creature is destroyed, it is sent to the mana pool as a Gem.
 * Dread - This creature can't be blocked unless by creatures from the same realm.
 * Flight - This creature can't be blocked unless by other creatures with flight.
 * Immune - This creature cannot be affected by several Spells and/or creature abilities (typically written as "Immune to ×")
 * L./D./W./F./E. Attacker - When attacking a creature from their respective opposing realm, this creature gains a boost in their Attack points.
 * L./D./W./F./E. Blocker - When blocking a creature from their respective opposing realm, this creature gains a boost in their Defense points.
 * L./D./W./F./E. Dread - This creature can't be blocked by creatures of the opposing realm.
 * Parry - This creature can block attacks that are directed to itself.
 * Piercing - This creature deals piercing damage even when blocked.
 * Rapid - This creature can attack instantaneously at the turn that it is summoned.
 * Spellproof - This creature can't be targetted by Spell, Equip or Arena cards.
 * Terminate - When this creature is blocked or loses a battle, send both creatures to the graveyard.
 * Unbreakable - This creature cannot be destroyed through battle.
 * Vitalink - Damage dealt by a creature with vitalink causes the player to gain that much VP.

Spell Cards
Spell cards are magical spells with a variety of effects, which can range from replenishing lost VP, to directly attacking the opponent's VP, to reviving destroyed creatures, to destroying all creatures on the field, among other effects.

Spell cards come in three varieties:


 * Normal Spell cards have a single, one-time effect before they go to the graveyard.
 * Constant Spell cards have effects that remain in play after activation until they are destroyed.
 * Quick Spell cards can be played from the hand at any point in the game as a counter.
 * Barrier Spell cards can only be played as Barriers in order to counter another player.

Spell cards are the most common and useful cards to be used as Barriers, due to their instantaneous effects. In particular, Barrier Spell cards are built specifically as Barrier cards, and cannot be played from the player's hand like a regular Spell card.

Equip Cards
Equip cards are cards that have to be "equipped" to a face-up creature on the field (hence the name) in order to take effect, after which they then give several advantages to the creature, such as increased Attack and/or Defense points, keyword abilities, or immunity from certain types or attacks or spells. Aesthetically, Equip cards are usually depicted as artifacts and other trinkets.

When put into play, Equip cards are attached beside the creature, indicating that they are "equipped". Barring a few exceptions, when a monster with an Equip card is destroyed, the Equip card is send to the graveyard alongside the monster. Certain Spell cards are also able to "unequip" creatures with Equip cards.

Most Equip cards are usually specific to a certain type of creature, and cannot be used to a creature of another type. For example, "Grimoire of Magic Arts", which is made for White Mage-type creatures, cannot be used by Wyvern-types, who instead have their own equivalent in the form of "Dragon's Horn". Equip cards cannot be used as Barriers.

Arena Cards
Introduced in the Evolved expansion set, Arena cards are able to change the entire state of play for its controller's or for both players' side of the field, giving several advantages to either or both players and their monsters. Unlike the other basic cards, Arena cards are played on an entirely separate spot on the field. Aesthetically, Arena cards are often depicted as various thematic landscapes.

Compared to buff-type Constant Spell cards, which only give out advantages toward the player who cast it, or Equip cards, which can only be attached to one creature each, Arena cards have special effects that affect both players to a degree. For example, "Vast Oasis" increases the power of all Water creatures on the field by +100. To counter this, certain Spells are able to destroy Arenas.

Typically, Arena cards give out advantages that lean toward the realm that they are from. Hybrid Arena cards were later introduced, which give out more powerful advantages for up to two realms at the price of requiring mana from two or more colors to cast. Arena cards cannot be used as Barriers.

The Five Realms
Each card in Kessenju belongs to one of five "Realms": the Realm of Light, the Realm of the Dark, the Realm of Water, the Realm of Fire and the Realm of the Earth. Each realm represents an archetype of concepts and virtues, which are reflected on the cards' design. The concepts behind each of the colors of the Five Realms are as follows:


 * The Realm of Light represents light, the beacon of peace and order, and draws mana from topazes. Creatures from the Realm of Light consist of human knights, warriors and mages, with some of them showcasing heavy "magitek" influences, and their spells tend to benefit the player or their creatures.
 * Keywords: Vitalink, Blocker, Attentive
 * The Realm of the Dark represents darkness, a symbol of death and despair, and draws mana from amethysts. Creatures from the Realm of the Dark consist of zombies, monsters, witches, and other macabre abominations, and their spells often draw from the player's own life source to cause misery for the opponent.
 * Keywords: Terminate, Dread, Spellproof
 * The Realm of Water represents water, and its inherent trickery and playfulness, and draws mana from sapphires. Creatures from the Realm of Water consist of wizards and spellcasters, as well as the sea monsters thet they have tamed in the past, and their spells rely heavily on "draw power" and manipulation.
 * Keywords: Parry, Spellproof, Blocker
 * The Realm of Fire represents fire, as well as its its sheer power and supremacy, and is draws mana from rubies. Creatures from the Realm of Fire consist of dragons, goblins, and orcs, among other warmongers, and their spells are often destructive in nature, often causing direct damage or mass destruction.
 * Keywords: Rapid, Piercing, Dread
 * The Realm of the Earth represents nature, the source of life and evolution, and draws mana from emeralds. Creatures from the Realm of the Earth consists of elves, animals and plantoid monsters, among others, showcasing the world's flora and fauna, and their spells focus on mana growth and natural strength.
 * Keywords: Charger, Attentive, Piercing

Besides illustrating their lore and philosophy, the five realms of Kessenju each form the "cycle of conflict", representing their individual strenghts and weaknesses, as well as their opposition against one another. In gameplay, this is represented by attacks from certain creatures of a certain realm being stronger when pitted against cards from their opposing realm. Certain creture effects and Spell cards are also meant to work specifically against their specific opposing realm.


 * Light outshines the Dark
 * Dark contaminates the Water
 * Water douses the Fire
 * Fire burns the Earth
 * Earth absorbs the Light

Most cards in Kessenju represent a single realm, as identified by their color, shown along the card's border. The cost to play them requires at least one mana of the same color as the card, and potentially any amount of mana from any other color. Hybrid cards were introduced in later sets and their borders are usually a mix of the colors of the two realms they represent. Their casting cost requires mana from at least two different colors.

The Five Realms of Kessenju can influence deck construction choices, with hybrid and multi-color decks being common in professional play so as to cover each others' weaknesses. There are no limits to how many colors can be in a deck, but the more colors there is in a deck, the more difficult it may be to provide mana of the right color.

Card Rarities
Kessenju cards have different levels of rarity, which defines the scarcity of the cards in boosters, as well as their percieved power. All in all, there are six rarity levels in Kessenju: Common, Uncommon, Rare, S-Rare, X-Rare and U-Rare.

Generally speaking, the higher the rarity of a card is, the more powerful they are, and the more sought-after they become, though this might not be the case for certain cards. Rarity levels in Kessenju cards are indicated by the tiny little symbol on the lower left side of the card.

Generally speaking, a single 10-card booster pack would usually contain 1 Gem, 6 Commons, 2-3 Uncommons and on occasion, 1 Rare. Finding an S-Rare in a booster pack is typically a matter of luck, while X-Rares cannot be found in any booster pack, and tend to be reserved for special releases.

The card rarity levels in Kessenju are as follows:


 * Common: Commons are indicated by a black circle inside a larger, white circle. Quantity-wise, commons are the most abundant cards, but are usually rather weak compared to other cards of much higher rarity.
 * Uncommon: Uncommons are indicated by a black diamond inside a larger, silver circle. Uncommons are largely a step above commons in terms of power, but are also more limited and scarce in terms of quantity.
 * Rare: Rares are indicated by a black star inside a larger, gold circle, with or without a holofoil wrap. Rares tend to be more powerful than both commons and uncommons but are also much scarcer in quantity than both.
 * S-Rare: Shorthand for "Special Rare", S-Rares are indicated by a black letter "S" inside a larger, titanium circle, and wrapped in holofoil. While consisting of the most powerful cards in the game, S-Rares are also among the hardest cards to find, with a 1/8 chance of finding one in a random booster pack.
 * X-Rare: Shorthand for "Extra Rare", X-Rares are indicated by a black letter "X" inside a larger, platinum circle, and wrapped in holofoil. X-Rares cannot be found in any booster pack, and are usually reserved for special releases, such as tournament prizes, collector's edition tins or as freebies in manga issues or video games.
 * U-Rare: Shorthand for "Ultimate Rare", U-Rares are indicated by a black letter "U" inside a larger, diamond circle, and wrapped in holofoil. U-Rares exist only in the Japanese OCG, where they are awarded to the winner of the yearly ACS-sponsored Kessenju World Championship.

Product Information
Kessenju trading cards are available in starter decks, structure decks, booster packs, collectible tins, and occasionally as promotional cards.

As in all other trading card games, booster packs are the primary avenue of card distribution. Typically, at least five or ten random cards are found in each booster pack, depending on the expansion set, and each set usually contains a larger number of cards, typically around 100-250 different cards per set.

Some cards have been released by other means, such as being bundled with video games and issues of CoroCoro Comic. These cards are often exclusive and possess the special "X-Rare" type of rarity or are never-before-seen to the public.

Expansion Sets
In its three years of existence in the North American market, the Kessenju TCG has has had 12 expansion sets released, across three blocks, or "sagas". An overseas release of the last set in the Endless War saga, "Fury of the Seas", was planned for 2007, before Topps dropped the Kessenju distribution license in November, 2006 shortly after the release of the 13th and second-to-last expansion set, "Zombie Army Twilight", which turned out to be the final TCG set.

However, this is not the case in Japan, where the Kessenju OCG continued to thrive, and is still going strong up to this day, with expansion sets released every three months, on a near-regular basis. From its launch in November 5, 2000 up until at least 2019, there have been over 100 expansion sets released for the Japanese Kessenju OCG.

TCG Sagas & Sets
Note that this list only denotes expansion sets that were released for the US-based TCG, which were distributed by Topps, and ran production from 2003 to 2006.

Original Saga

 * KSJ-01: Ultimate Battle Beasts (May 19, 2003)
 * KSJ-02: Evolved (August 5, 2003)
 * KSJ-03: Wyverns' Uprising (November 14, 2003)
 * KSJ-04: Great Mage Strife (February 25, 2004)

Primordial Saga

 * KSJ-05: Primordials (April 20, 2004)
 * KSJ-06: Wrath of the Earth (July 6, 2004)
 * KSJ-07: Amalgamation (October 18, 2004)
 * KSJ-08: Reign of Chaos (January 19, 2005)
 * KSJ-09: Ancient Judgment (May 2, 2005)

Endless War Saga

 * KSJ-10: Elves of Discord (September 23, 2005)
 * KSJ-11: Goblins Unleashed (January 11, 2006)
 * KSJ-12: Order of Knights (April 29, 2006)
 * KSJ-13: Zombie Army Twilight (September 8, 2006)

Manga
Kessenju was adapted into a manga series by Hideaki Terasaki, and published by Shogakukan, in their CoroCoro Comic magazine. The original manga series ran from 2000 to 2005, and was compiled into 14 tankoubon volumes. It was then followed by ''Kessenju! REVOLUTION, which ran from 2005 to 2008, which was later followed by Kessenju VICTORY'', which ran from 2008 to 2011. VICTORY was then followed up by Kessenju BRAVE which ran from 2011 up until 2014, which was then followed up by Kessenju CLASH, which ran from 2014 to 2018. As of this writing, the current ongoing series is Kessenju ACES, which began in September, 2018. As of this writing, none of manga series have been licensed for the U.S., though fan-made scanlations do exist.

Anime
Main article: Kessenju!: Ultimate Battle Beasts

The first television series, titled simply as Kessenju! originally premiered in Japan on March 3, 2002 and ran until July 17, 2005, spanning three seasons throughout its run. It was then followed by a sequel series, ''Kessenju! REVOLUTION'', which premiered on 2005. REVOLUTION spanned three seasons up until it was concluded in 2008, after which it was succeeded by Kessenju VICTORY, a direct followup to REVOLUTION, spanning three seasons from 2008 to 2011. VICTORY was then followed up by Kessenju BRAVE, which ran from 2011 until 2014, spanning three seasons. Eventually, BRAVE was succeeded by Kessenju CLASH, which ran for three seasons from 2014 to 2018. The current ongoing series is Kessenju ACES which premiered in 2018 and is still ongoing to this day. In 2013, a four-episode OVA adaption of Kessenju DD was released.

All three seasons of the first series were licensed for English adaptation, broadcast, and release by Nelvana. Nelvana's dub of the series, entitled Kessenju!: Ultimate Battle Beasts in order to match the card game's localized name, features several visual edits and name changes, in order to better suit an American audience. The series was broadcast on the sibling cable channel YTV in Canada and in ABC Family in the United States in 2003. Following the discontinuation of the card game in 2006, Nelvana opted not to license the sequel series Kessenju REVOLUTION.

Video Games
Main article: List of Kessenju video games

Over the years, ACS has published several games based around the Kessenju franchise, mostly ranging from digitized conversions of the card game, to role-playing games featuring characters from the various Kessenju manga and anime series.

Light Novel
Kessenju DD: Duel Diary is a spinoff light novel series written by Hideaki Terasaki for ACS' DokiDoki Bunko light novel imprint, published from 2007 to 2011. It is a sequel to the original manga series, starring the main cast, now having grown up as teenagers, as they rediscover their passion for the game. As it is intended for a much older target demographic than the manga, which was intended for the kodomo demographic, Kessenju DD features several darker elements than its original source material.