Shibuya Taikai is a popular young actor with excellent acting skills and a charming smile. Women are crazy about him, but Taikai has never been in love in his life. He has a 4-year-old sister named Rizumu, who attends nursery school.

One day, Rizumu comes back home with a scratch from the nursery school. Taikai is concerned enough that he passes up on a drama series acting offer and decides to take Rizumu to school and pick her up after school. At his sister's school, Taikai Shibuya meets Rizumu's teacher, Aota Aika. He gets attracted to her. Meanwhile, Aika is a devoted nursery school teacher who likes children. She has a warm heart and cares about other people.