Rinku is a child-demon who uses yo-yos as his weapon and is part of the Jolly Devil Six in the Dark Tournament. He has a playful and childish demeanor, which often irritates those around him. Despite this, he shares a close friendship with his teammate Chu. Rinku wields special yo-yos known as Serpent Yo-Yos, which he can control using his aura to ensnare or strike his opponents. During the Makai Tournament, Rinku enhanced his skills to manipulate the yo-yos with both his fingers and toes. Kuwabara also mentions that Rinku possesses an incredibly powerful kick.
In the Dark Tournament Preliminaries, Rinku faced off against Kuwabara. Both were knocked off the arena, but Rinku managed to recover and used his yo-yos to trap Kuwabara, preventing him from getting back up, thus securing his victory. Following this, Rinku makes several minor appearances, such as during the fight between Yusuke Urameshi and Younger Toguro. In the Saga of the Three Kings, he trains under Genkai and advances to become an A-Class demon. Although he passed the preliminaries in the Makai Tournament, he did not progress very far in the competition.
