Uryuu Kamihate aims to enter medical school but finds his new foster home is a shrine where he must marry one of the three Amagami sisters and take over the temple.

A young man is transported into a video game world dominated by females.

The atmosphere in True Cross Academy is lively and boisterous in the days leading up to the grand festival held once every 11 years. During this time, Okumura Rin is entrusted with the responsibility of suppressing the berserk Phantom Train. In the midst of his mission, he meets a devil whose appearance is that of a young boy.