Five years ago, during the summer, a family of four got into a car accident on their way back home from an amusement park. The family members are Hana Kubo, her mother Mayuko, her father Shiro and her younger sister Runa. Due to the car accident, all of the family members were injured: the mother Mayuko fell into a vegetative state, the father Shiro injured his right leg, younger sister Runa received a severe burn on her face, and Hana was deeply wounded psychologically. One day, Hana meets high school student Jun Yotsui. His mother suffers from a mental illness and he looks for the reason why. Five years after the car accident, Hana's father Shiro suddenly brings Mayuko home after he informs them that she finally awoke from her vegetative state. Hana is happy to have her mother Mayuko back home, but she soon feels uncomfortable around her.