Within Yoshiwara, there is a self-defense unit by the name of Hyakka 百華, comprising a team of female ninjas led by Tsukuyo.
All members are characterised by facial scar(s). Some members are ex-prostitutes who were persecuted for trying to escape, but were secretly recruited by leader Tsukuyo 月詠 into the ranks. For many their scars are the reason for joining the Hyakka as their percieved worth as prostitutes was seemingly lost because of the scars. Many of them, like Hinowa consider Seita like a son.