Custom Robo (Nintendo Cinematic Universe)

Custom Robo is a Japanese anime miniseries.

Summary
A young man in search of his father joins the Robo Commander bounty hunter organization Steel Hearts.

Plot Elements

 * Before his father's mysterious departure, Hero was given a watch and told to keep it safe.
 * In the present, Hero suddenly receives a letter stating that his father has just died.
 * In honor of his father's wishes for him to become a Robo Commander, Hero sets out to do so - despite knowing nothing about robos. He eventually manages to join up with a group of bounty hunters known as the "Steel Hearts", where he meets Ernest, Harry, and Marcia.
 * A fellow member of the Steel Hearts, Harry, teaches Hero how to command robos and helps him receive his license, which allows Hero to battle with robos legally.
 * After a few minor errands, Hero and company discover the self-guided Robo known as 'Rahu'. Later, after passing a test and obtaining a Class "S" license, Rahu's past is revealed, and Hero finds out that Rahu is an invisible organic being who had accidentally been fused with a toy robot.
 * Before the time of the domed city, the world was attacked by a powerful entity - now known as Rahu.
 * Eventually, Rahu came to possess a child's toy. This toy was very similar to a Robo.
 * By popularizing Robo battling, the government gave the people a way to fight the entity.
 * Rahu was soon damaged enough to be driven into dormancy for a long period of time but has now awoken.
 * Hero and the rest of the police force leave the safety of the dome to defeat Rahu again, along with the organization known as the Z-Syndicate, who are trying to control the entity for their own ends.
 * After defeating the syndicate, Hero meets an old friend of his father's, and the brother of Marcia of the Steel Hearts, a spy named Sergei. He originally joined the Z Syndicate to stop Rahu, but was forced to work with Oboro, who wanted to control Rahu for his own means.
 * Eliza and Isabella, two other members of the Z Syndicate, also wanted to control Rahu.
 * Sergei showed Hero an old recording of his father's last message to him. In the recording, Hero's father explains that he left to form the Z-Syndicate in an attempt to inform the people of Rahu's impending attack. The other members soon lost sight of his vision and betrayed him in an attempt to the seize control of the Syndicate and Rahu.
 * Hero, Harry, and Marcia eventually defeat Rahu, ensuring the world's safety - for a while.