Takuya, an 11-year-old boy, looses his mother in a car accident. Because his father is so busy, he starts to look after his baby brother, Minoru. As an elementary school boy, it is not easy to manage his school life and caring for his brother. He often feels like giving up. However, Takuya cannot turn his back on his little brother who totally depends on him.
Takuya runs into two of his classmates, Gon-chan and Akihiro, in his brother's nursery school. They also have younger siblings that they need to take care of for their busy parents. As a result, they become good friends and advisers to each other.
This story depicts family bond, brotherhood, and friendships that would move audience's hearts.