After the Great Earthquake in Northeastern Japan, Mitsuo is sent to a mental hospital from the strain of grief from working to clear out the debris of the disaster. When he is released 3 years later, he feels a moment of happiness as he is welcomed back by his brother Yuta, his wife Yoko, their first daughter Chie, and their second daughter Itsuki, who has a down syndrome. The next day, Chie wishes to go to the amusement park, and Mitsuo takes Chie and Itsuki there. But these happy moments don't last long, and the incident happens at the park. Chie dropped Itsuki on the concrete when Mitsuo took his eyes off of them. Yoko cannot accept Itsuki's death, madly questions Chie and Mitsuo. In this pressure, Chie lies that "Uncle Mitsuo dropped Itsuki." As Yoko goes through a mental breakdown from the shock. Becoming full with regret day by day, Yoko accuses Yuta and questions if he felt relieved that Itsuki died. Hearing this fight between her parents, Chie's heart was also slowly being broken.