Tendou Kazuomi is a second-year high school student. One night, he saved a little girl who was about to be kidnapped, but she turned out to be the younger sister of Takane Mizuki, the famous cool and beautiful girl at school. Living alone and feeling lonely, the younger sister takes a liking to him, and Kazuomi is confronted with a variety of sweet demands. The three of them spent their days their days eating together at the same dining table. Kazuomi and Mizuki became friends as they listened to her little sister’s wishes. A sweet and tender big brother’s romantic comedy. This is a story about three people who were a pseudo-family becoming a real family.