Bunny Drop (うさぎドロップ Usagi Doroppu?) is a Japanese josei manga series by Yumi Unita. It was serialized in the monthly magazine Feel Young from October 2005 to April 2011 and the chapters were collected into eight wide-ban volumes as of October 2010 by Shodensha. The series has been licensed in English by Yen Press with three volumes released as of March 2011. An anime adaptation by Production I.G began airing in Japan from July 8, 2011. A live-action film was also made and is set to premier in Japan on August 20, 2011. A spin-off series by Unita will begin serialization in the July 2011 issue of Feel Young. The plot follows thirty-year old Daikichi as he becomes the guardian of Rin, the illegitimate six-year old daughter of his grandfather.
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 mother of Koki Nitani, a single mother, who gives him advice on raising Rin. After a year has passed, Daikichi acknowledges his sacrifices for Rin has 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 Koki, and her decision for a career. Rin discovers that she has no family ties to Daikichi and the series ends with Rin living with Daikichi.(Via Wiki)