Kippei Katakura is a 17-year-old high school student who is suddenly in charge of raising his 5-year-old cousin Yuzuyu Sakashita, and goes through the trials of raising her throughout the series.
He is a handsome boy with blond hair and hazel eyes.
Although Kippei is well known around his school for being a playboy, he is still popular due to his friendly and easygoing personality. In the beginning he never took his relationships with girls seriously, and never took their feelings into account. However, once he is given the task of taking care of Yuzuyu, he gives up those habits in favor of giving her his full attention. Over the series he realizes that how he had been treating his female peers was wrong and that they deserved more respect and care.
He seems to be a natural at sympathizing with younger children and is willing to learn as much as he can in order to make Yuzuyu happy. He is easily swayed by Yuzuyu's cuteness and takes pride in how he takes care of her.
Kippei can be rather dense sometimes as stated by his family members.
As seen in episode 8, he becomes so used to having Yuzuyu around all the time that he is practically lost without her. He becomes incredibly bored and even goes so far as to consider the possibility of looking for a girl to occupy his time with.
He soon became interested in Kokoro Tokunaga, but she initially rejected his advances because she thought he was a playboy. She softened a little after seeing how he cared for Yuzuyu and admitted that she did like him, but she still did not want him to get too close to her. Despite this he continued to do what he could for her, to the point where he told her that even if he could never hold her hand again he still wanted to be by her side. She began to fully realize just how much he truly cared for her and finally accepted him and eventually they became a couple.
- Misako Katakura (Mother)
- Reiko Katakura (Older Sister)
- Satsuki Katakura (Younger Brother)
- Miyako Sakashista (Aunt)
- Yuzuyu Sakashista (Cousin)
- Kokoro Tokunaga (Girlfriend)
- Kippei loves strawberry milk, as he is seen drinking it on multiple occasions.