After the young vampire Chinen Yuri confessed to his crush Rina in college and was rejected, he gave up the cruel words of "be careful when your children come out of school in the future" and left his hometown out of strong self-esteem. After 20 years, Chinen finally remembered his vow and returned to his hometown after many years of absence. He originally wanted to pursue Rina's daughter. If he couldn't be Rina's husband, he would be the husband of Rina's child. However, what he didn't expect was that Rina gave birth to a boy...