The charismatic leader of the "Five Leaves." A mysterious person, he dislikes telling about his own past and lives in a local brothel, protecting and flirting with the women working in there. Distinguishable by his light colored hair and his tanned skin, he is often seen smoking a pipe. At the beginning of the series he is calm and carefree, seemingly living life to the fullest and intent on living in only the present, as he says to Masanosuke. He even does him a favor by recruiting Masanosuke into the Five Leaves gang at the point where he is at his weakest socially (because he is very shy) and financially. His reasons for befriending the samurai at first was because he was so naive, but over the course of the series Yaichi has a sort of falling out with him because Masanosuke was "annoying." Yaichi eventually becomes the subject of Masanosuke's personal investigation of his past, something Yaichi has long repressed.