High school student Yuge Itsuki is sent off to the magical world of Granvania with his childhood friend Konatsuki Mahiru. Itsuki was summoned to save this world, but to accomplish this mission he must perform Love Rituals?!
Itsuki and Mahiru performed their first Love Ritual and a Star Child was born! Later, Itsuki starts to bond with one of the maidens, Ruka, at the cherry blossom viewing welcome party.
Itsuki bonds with Yuzuha, Maiden of Pisces. She works as a painter, but uses a coffin as bed for some reason, and drew what she saw in dreams while sleeping inside it. She seems to be in a slump, so Itsuki asks her out on a date as a change of pace.
A beach tour was organized to deepen Itsuki's bond with the maidens. However, that information was leaked to the biggest playboy in the academy, Seiya, who followed them in an attempt to seduce the maidens.
Itsuki finds out about the Stardust Labyrinths where the Impurity Lords dwell, as well as the 13th labyrinth and the existence of the 13th maiden. He sets out to find the maiden, however the maiden might actually be a boy?!
A girl claiming to be the 13th maiden shows up before Itsuki. She sets out to confess her love while wearing an outlandish '80s outfit. However, Itsuki fails to notice, and continues his search.
