When the gates to the realms of gods and demons swung wide open, the world transformed overnight. A decade later, a lad named Tsuchimi Rin found himself in the care of two princesses hailing from these mystical dimensions. Juggling a semblance of normalcy at school with his childhood chum Kaede, Rin also played the role of neighbor to the princesses and their formidable fathers, the Lords of these realms. As the keeper of their hearts' secrets, Rin must navigate this intricate web to safeguard their emotions and his own sanity.