The drama takes place during the Meiji era. Matsuzaka Kurenai is just your ordinary wife and mother. Stays home and takes care of her son and the house while her husband is away at work. But she has a disturbing past... Her father was once what we'd today call a mercenary - a person who basically kills people for justice and money. As a little girl, Kurenai witnessed her father on the job killing someone. She since then hated him for what he was. As the years went by, she learned the art of short knife fighting. In episode 1, Kurenai gets personally involved in a situation. She discovers that a women friend of hers hired a group of mercs to take someone out. But before they could be killed, they killed her and her family. Ebisuya Bunzo is the head of the mercs, with members Oaki, Kagenosuke, Akane and Ryuji. Kurenai asks if she can get involved, but Bunzo (who also happens to be an ex-partner of her father's) tells her she must take part of the money or get lost. So she ends up taking the money. Just like her father, Kurenai becomes a hired merc.