Masanosuke "Masa" Akitsu is a wandering ronin drifting through Japan's tranquil Edo period. Although he is a skilled swordsman, Masa's timid nature has earned him the reputation of being "unreliable," and he is frequently and suddenly dismissed by his employers, causing him to doubt his resolve as a samurai. At his lowest point, Masa is approached by Yaichi, a carefree man dressed in pink who seemingly hires him on a whim to serve as his bodyguard. Unbeknownst to Masa, the position is not as innocent as it appears, and he is pulled into the illicit activities of the group led by Yaichi. As he becomes more deeply involved with the gang known as the Five Leaves, Masa struggles with his own principles. Nevertheless, his curiosity drives him forward to uncover the past and motivations of this mysterious band of outlaws.