Shizunari Itsuki doesn’t have any relatives, lost his memories and even has a fear of women. In order to overcome this fear, which was causing problems in his adopted family, he was enrolled into the Saint Tiphereth Girl’s School as a girl under the assumed name Shirahane Itsuki. However, any hopes he had of an uneventful school life were destroyed when model student and star of the school Hirasaka Eri, known as the "Holy Mary", found out his secret. Luckily for him, he also discovered her true nature in turn, and so they agreed to a mutually beneficial partnership. They would not reveal each other's secrets and would support one another to the best of their ability. And in order to help him get rid of his gynophobia... "I, Hirasaka Eri, offer you my body." She would help him get used to seeing and touching a woman's body, but it was yet another secret that nobody could find out. Yet his problems didn't stop there. With him and the famous "Holy Mary" spending so much time together, it was only natural that other girls in the school became jealous of their close relationship. He soon had many enemies, but then another girl vowed to protect him. That girl was Mitsurugi Maya, who was known as "Arthur", and was the head of the school's disciplinary committee, The Chivalric Order of the Church. She was the only one at the school considered a rival to Eri in terms of popularity. "Don't worry, Itsuki, I will keep you safe!" With Eri and Maya competing over him in a war of charisma, the school itself split into two factions, and all eyes on him, will it be possible for Itsuki to achieve the goal he came for?