Ryujiro Mizunuma

Ryujiro is arrogant, cruel and comfortable intimidating people he considers weaker than himself. He participates in bullying Kiku and relies on his gang to reinforce his position.

He is particularly dismissive of Takeru when the latter intervenes. Rather than simply allowing Kiku to leave, Ryujiro turns the confrontation into a duel and uses Takeru's visible fear against him.

His confidence deteriorates once Takeru begins fighting back effectively. Ryujiro is accustomed to controlling the confrontation, and he struggles when his opponent refuses to remain intimidated.

Ryujiro uses a Zombie Deck built around low-ATK monsters and graveyard-related effects. Cards such as Plague Wolf and Skull Conductor help him establish his field before bringing out stronger threats.

Despair from the Dark is the centerpiece of his strategy. Ryujiro can use Edge of Darkness to search for and summon it, giving him a powerful monster after developing his field with weaker Zombies.

He is capable enough to place the inexperienced Takeru under considerable pressure. Takeru requires encouragement from Flame while remembering their duel before he can overcome his fear and formulate a winning response.

Ryujiro appears primarily through Takeru's memories of his life after the Lost Incident. He and his group bully Kiku, prompting Takeru to intervene despite still struggling with severe fear from his childhood experiences.

Ryujiro challenges Takeru to a duel and summons Despair from the Dark. The monster's appearance triggers Takeru's memories of the Lost Incident and initially leaves him unable to continue effectively.

With Flame encouraging him through the memory, Takeru recalls finding the courage to stand again. He combines Rising Fire and Tempest Fire to destroy Ryujiro's monsters and defeat him, making the confrontation an important memory in Takeru's recovery from his fear.

Takeru Homura confronts Ryujiro when he sees him bullying Kiku. Ryujiro exploits Takeru Homura's fear during their duel, but Takeru Homura eventually regains his determination and defeats him.

Kiku Kamishirakawa is targeted by Ryujiro and his group of bullies. Takeru Homura intervenes specifically to protect Kiku Kamishirakawa.

Kotaro Mizunuma is Ryujiro's older brother and another member of the group involved in bullying Kiku Kamishirakawa.