Conception

On the day of his high school graduation, Itsuki learns from his cousin Mahiru that she is pregnant. Suddenly, a glowing gate appears and pulls them both into the world of Granvania. There, creatures known as "Impurities" are disrupting the Stars, throwing the land into chaos. Itsuki discovers he is destined to meet the "Star Maidens" and is seen as Granvania's final hope. His mission is to father "Star Children" and fight the Impurities-but unless he succeeds, he may never return home.