Haiyama

Haiyama initially presents himself as quiet, frightened and subordinate to Kujirada. This is an act that conceals the actual balance of power between them.

In private, Haiyama is domineering and sadistic. He uses money to manipulate Kujirada and expects obedience from people he considers beneath him, punishing resistance with a whip. He applies the same attitude to his Digital Pet, valuing power and obedience rather than affection.

His treatment of others is rooted in control. Kindness offered by Yugi does not change his behavior because Haiyama interprets relationships primarily in terms of masters and subordinates.

Haiyama owns a Gold Digital Pet, one of the electronic creatures popular among Domino High School students. Digital Pets develop according to their owner's treatment and can exchange data or fight when their devices are connected.

During his confrontation with Dark Yugi, their Digital Pet battle becomes a Shadow Game in which the electronic creatures manifest as apparently physical beings.

Haiyama also carries and uses a whip to intimidate people and his own Digital Pet.

Haiyama appears during the Digital Pet craze while Yugi believes he is being exploited by Kujirada. Yugi attempts to help him and even gives him a Digital Pet so they can participate together.

The apparent victimhood is eventually exposed as deception. Haiyama reveals that he has actually been manipulating Kujirada with money and attacks Yugi and Hiroto Honda when they interfere. He attempts to treat Honda as another "pet."

Dark Yugi challenges Haiyama to a Digital Pet Shadow Game. After Haiyama's creature loses, he continues abusing it, and his Penalty Game causes him to experience the illusion of his own pet turning against and devouring him.

Yugi Mutou initially regards Haiyama as a classmate who needs help. Haiyama rejects Yugi Mutou's kindness and attacks him, leading Dark Yugi to challenge him to a Shadow Game.

Kujirada appears to be Haiyama's bully. The apparent relationship is deliberately misleading: Haiyama is actually manipulating Kujirada through money.

Hiroto Honda intervenes after discovering Haiyama's behavior. Haiyama attacks Hiroto Honda and declares his intention to make him a personal "pet."

Miho Nosaka is present during the confrontation in which Haiyama's true behavior is exposed.