30-year-old bachelor businessman Daikichi Kawachi encounters Rin, a girl he's never seen before, at his grandfather's funeral. Surprisingly, the 6-year-old girl turns out to be his grandfather's love child. Daikichi doesn't like children, but the cold attitude of his relatives towards Rin makes him uncomfortable. And then, the relatives' meeting to decide who will have custody of Rin begins at last...

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...

Daikichi finally meets Rin's mother, Masako, and he's shocked by her frankness. When they part, Masako asks Daikichi for a favor, and it's an issue that Daikichi can't avoid, as long as he's going to raise Rin. Daikichi tries to resolve it by having a heart-to-heart conversation with Rin, but he gets an unexpected answer...

When Rin enters elementary school, Daikichi proposes planting a tree to commemorate the occasion. Rin plants a loquat seed in the yard, but there's no telling whether it will actually put forth buds. Thinking that perhaps Souichi planted something to mark Rin's birth, Daikichi has another visit with Masako...

At school, Rin is concerned that the disobedient Kouki is getting off track and getting a bad reputation. Meanwhile, when a typhoon hits, Kouki and his mom take shelter with Daikichi and Rin at their house.

It's the first anniversary of Grandpa's death, which means Rin and Daikichi have been living together for about a year now. Daikichi mulls over what he's lost and what he's gained since Rin came into his life...

After visiting a festival, Kouki is still not tired, so Daikichi suggests a little detour on their way home, thus showing Rin, Kouki and Yukari his "secret place".