What kind of clothes to buy her? What to feed her? What to do about nursery school? Daikichi's new life raising a 6-year-old girl is an uninterrupted stream of bewilderment. Rin looks anxious on her first day of nursery school, so Daikichi does a "pinky swear" with her, promising to pick her up as soon as he can. And Daikichi, who has no confidence he can live with Rin for long, starts thinking about meeting Rin's mother...

Rin befriends Kouki, a boy she met at the local nursery school, while Daikichi's pulse races a bit when he meets Kouki's beautiful single mother. Later, the modem Daikichi found leads him to his grandfather's last words. And from there, he receives a contact number for Rin's mother, Masako...