Guruguru

Guruguru is shy, anxious and easily overwhelmed. His nervousness makes him less assertive than the main members of the Rush Duel Club, and he frequently reacts to danger by panicking rather than confronting it.

He nevertheless loves being around Yuga and the others. Their enthusiasm for Rush Dueling fascinates him, and he gradually becomes comfortable enough to participate in their everyday activities.

Guruguru also displays a strong desire to belong. The companionship offered by the Rush Duel Club becomes particularly important to him, even when he cannot explain why ordinary Dueling knowledge sometimes feels strangely unfamiliar.

Guruguru is familiar with Rush Dueling through his time around Yuga's group, although he initially lacks the confidence and established Deck associated with the series' major Duelists.

He is physically unremarkable compared with characters such as Luke or Tiger. His importance instead comes from his unusual circumstances and the mysteries surrounding his memory.

Once his suppressed identity returns, he uses a Reptile Deck built around monsters such as Ecdysis Caesar the Great Emperor Penguin and develops into a dangerous Rush Duelist.

Guruguru joins Yuga and his friends shortly after the arrival of the Goha siblings, becoming a recurring observer and companion during their challenge against the returning presidents.

His presence initially seems incidental. He attends Duels, spends time with the group and gradually becomes integrated into their circle without providing a clear explanation of where he came from.

Guruguru is eventually revealed to be Yuga Goha, the missing sixth Goha sibling. His memories had been erased, leaving him genuinely unaware of his identity while he lived alongside Yuga's group.

After Monster Reborn restores his memories, his personality changes dramatically and he becomes an antagonist, using his Reptile Deck while attempting to erase other people's memories of Rush Dueling.

Yuga Ohdo befriends Guruguru without knowing the truth about his past. Guruguru admires Yuga Ohdo and enjoys belonging to his group.

Lucidien "Luke" Kallister, Romin Kirishima and Gakuto Sogetsu likewise accept Guruguru as part of their circle.

Yuuro Gouha, Yuujin Gouha, Yuuka Gouha, Yuran Goha and Yuuou Gouha have a hidden connection to Guruguru. They are his siblings, with Guruguru actually being the missing Yuga Goha.

Otes becomes important to Guruguru's later story through the struggle over the memories and future of Rush Dueling.