18+ Oyome-san Kouho ga Arawareta! Command wa?

One day, three girls suddenly appear in front of Sora on his way to school. They say that they are sisters and wife candidates of Sora.... Mikoto, Nanaka and Yuki. Sora is totally confused what to do.... However, they start living at his house. "What's going on...?" No one knows why....

(Source: ErogeShop)