Super Mario Bros. II (Nintendo Cinematic Universe)

Super Mario Bros. II is a Japanese anime film.

Summary
After successfully defeating Bowser and saving Princess Peach, Mario and Luigi are hailed throughout the Kingdom as heroes. But little do they know that a young but dangerous new enemy is arising, with a thirst for vengeance against the brothers.

Plot Elements

 * One night, sometime after the events of the first film, Mario has a dream about climbing a staircase and ending up in a strange world.
 * The next day, Mario goes on a picnic with Luigi, Princess Peach, and Toad.
 * Upon arriving, the group discovers a cave with a long staircase, similar to Mario's dream.
 * The group climbs the staircase, only to find themselves in the dreamland Subcon.
 * One of Subcon's residents, Imajin, tells the heroes that an evil king named Wart has terrorized the land and begs the heroes to save Subcon.
 * Mario and his friends defeat Wart and his minions, saving the land of Subcon.