Isshiki, who was saved in the past by Sister Seika, wants to declare his love for her on her birthday. But while preparing for his confession, he gets possessed by Asmodeus, the demon of lust. However, in order to exorcise the demon and downplay the other girls' suspicions, Isshiki must never get excited, no matter what lewd acts he's subjected to!Enjoy this romantic comedy of the war between the demon of lust and the sisters of the church with Isshiki caught in the middle!