Masanosuke is a skilled samurai hailing from a prominent family. He is very shy and despite his incredible talent, he is often fired because of his shyness around other people. He left home because he initially felt he didn't belong in his hometown. He works with Fives Leaves after Yaichi hired him as a bodyguard; however, he was unaware of the group's illegal activities, which involved kidnapping. He admires parts of Yaichi's carefree personality and even idolizes him somewhat, but is curious about his leader's past.