When 30-year-old Daikichi returns home for his grandfather's funeral he learns about the existence of Rin, his grandfather's illegitimate six-year-old daughter by an unknown mother. The girl is an embarrassment to all his relatives and is treated as an outcast. Annoyed by their attitude, Daikichi decides to take care of Rin himself, even though he is single and has no experience raising a child. As Rin becomes part of his life, Daikichi experiences the hardship of a single parent. He is befriended by the single mother of Kouki Nitani, a friend Rin meets in nursery school, who gives him advice on raising Rin. After a year has passed, Daikichi acknowledges his sacrifices for Rin have been worth it. The first half of the series focuses on Daikichi's perspective and struggles raising Rin. Ten years later, Rin is a high-school student and the remainder of the series focuses on her trying to figure out how to deal with her feelings for Kouki, and her decision for a career. Rin discovers that she has no family ties to Daikichi and the series ends with Rin planning to have a child with Daikichi.