Toriko no Chigiri: Kazoku no Tame ni Shintai o Sashidasu Ane to Imouto

The main character's name is Yakumo Rio. In childhood she lost her parents and with her younger sister MIA moved into the house of his grandfather. New "family" was somewhat different from the usual. Grandpa Rio was a Yakuza, the head of the Yakumo family. An elderly relative did anything to the criminal Affairs of the family did not concern the innocent sisters. But clouds hung over them, a peaceful life, when grandpa was ill. Competitive clan families Mitsuru immediately jumped at the opportunity to expand their sphere of influence. At the next meeting of all the clans, the head of Mitsuru was going to announce that takes control of Yakumo family. Help "beheaded" family, if you can call it help, comes family Innami. The head of the clan, Inami Kozo offers her "intercession" and as a reward requires you to make full use of the body of one of two sisters. And Rio decides to sacrifice himself for the family...