Kumadori (クマドリ, Kumadori) is one of the last members of CP9 to be revealed, and is recognizable by his large frame, huge mane of pinkish hair, and a right eye that never seems to be open. He seems to honor the samurai honor code very heavily as he comically attempts to take his own life after dishonoring himself. As he accepts the blame for nearly anything, even faults of others, this happens quite often in his appearances. Before he commits seppuku, however, he instinctively uses tekkai every time, unintentionally saving his own life.

He seems to have strong feelings for his deceased mother, beginning to sob, even while fighting, at the very thought of her. He claims her "divine protection" is the reason for his failed suicide-attempts. These dramatic statements are somewhat undercut by Oda's revelation that his mother is in fact alive, and working as an assassin. [3] He claims to dislike lies, though he seems to have no trouble with melodramatic stories. Kumadori is a sennin (仙人, a type of hermit in Japanese mythology who can control even their body's autonomic functions, as well as live forever, similar to fellow Shonen Jump character Jiraiya of the popular series Naruto), which explains his sudden weight gain/loss as well as the ability to control his hair.

Kumadori is a very loud character, and utters very few sentences not written in bolded fonts and ending with exclamation marks. He has the strange habit of yelling something resembling "YOYOI!!" rather often. He tends to repeat or draw out syllables and words in the manner of kabuki actors. Kumadori's name most likely comes from the Japanese word kumadori (隈取り, a type of makeup used for kabuki), as his features look very similar to those of kabuki actors in their makeup. His body positions (especially his penchant for holding one hand out in front of him) are also reminiscent of mie poses, and his vocal inflection is similar to that of kabuki actors. His fighting abilities seem to revolve around controlling his hair, using it to grab his enemies and attacking them. He also has a shakujō that he occasionally uses in battle. He also has a penchant for spouting off haiku when fighting.

Kumadori was originally fighting with Nami, who was at a severe disadvantage. However, Chopper appeared and helped Nami (after Nami had already stolen Kumadori's key) to escape, becoming Kumadori's opponent. Despite Kumadori's advantage of being a sennin, Chopper consumed a third Rumble Ball, and his subsequent "Monster Point" form severely injured Kumadori and threw him all the way back to the courthouse.