Kouta is the only son and heir to the Mikomori family temple in a small provincial town. However, he has no desire to inherit the temple and is determined to finish his higher education. However, his recently married father suddenly disappears and leaves his wife Erina and her sister Motoka for Koutou. A chain of incomprehensible events occurs in this story: our hero's supposed wife or fiancée Mai appears, his childhood friend Mio tries to get Kouta's attention and finally Erina suddenly declares that she wants to have his child...