30歳の独身サラリーマン・河地大吉(かわちだいきち)は、祖父・鹿賀宋一(かがそういち)の葬儀で見知らぬ少女・りんと出会う。その6歳の少女は、祖父の隠し子だった。子供嫌いの大吉だが、親戚たちのりんへのよそよそしい態度に違和感を募らせ、りんを引き取ることに。
While attending his late grandfather, Soichi Kaga's funeral ceremony, office worker Daikichi Kawachi learns about the existence of Souchi's illegitimate 6-year-old daughter, Rin. Due to her illegitimacy, other family members treat her as an outcast and refuse to adopt her. Daikichi decides to take matters himself and raise Rin.