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

Based on the erotic game by Guilty eX.

Two sisters, living peacefully with their grandfather who heads a Yakuza group, face a dilemma when their grandfather falls ill and another rival group starts putting pressure.

The only way out is to accept the deal with another Yakuza group for support in return for one of the girls.