Kenichi is not a character in the anime Bunny Drop. The protagonist of Bunny Drop is a 30-year-old bachelor named Daikichi Kawachi. It appears there may have been a confusion with the actor Kenichi Matsuyama, who portrayed Daikichi in the live-action film adaptation of Bunny Drop.

Daikichi Kawachi is an unmarried office worker whose life changes dramatically following the death of his grandfather. At the funeral, he discovers that his grandfather had an illegitimate six-year-old daughter named Rin. When the rest of the family views the child as an embarrassment and refuses to take responsibility for her, Daikichi becomes frustrated with their attitude and decides to care for the girl himself, despite having no experience with children.

Initially, Daikichi is completely unprepared for the challenges of parenthood. As a long-time bachelor, he has much to learn about the daily responsibilities of raising a young child. His motivation stems from a strong sense of duty and compassion; he cannot accept that his family would abandon a child simply because of the circumstances of her birth. This decision requires significant personal sacrifice, including willingly taking a demotion at work to forfeit mandatory overtime, thereby gaining more personal time to properly raise Rin. His commitment to Rin also leads to positive lifestyle changes, such as quitting smoking and becoming more diligent about household chores.

Throughout the story, Daikichi is frequently mistaken for Rin's biological father by strangers, and he typically does not correct this assumption by explaining that he is actually her nephew. Despite being only thirty years old, he has a negative reaction to being called an old man or uncle. His key relationship is with Rin, whom he raises as an adoptive parent, and his character development centers on his gradual growth from an inexperienced bachelor into a devoted and responsible parental figure.