Nijuu Mensou no Musume

Chiko is the daughter of the wealthy Mikamo family who has to live with her aunt and uncle after her parents passed away. Because her aunt wants to inherit the Mikamo family's wealth, she gives Chiko poisoned food. One day, however, she's kidnapped by the Nijuu Mensou (20 Faces) and decides to join his clan.
(Source: ZOMG)