Muroi, who retired from the police early, took in the children affected by the incident and moved to Tohoku. Although he was told cold words from those around him, he lived quietly while protecting his children. However, the body of the perpetrator of the special fraud and robbery was found deep in the mountains, and the village fell into chaos.
A body found in the mountains of Tohoku, where Muroi has moved, is linked to the Rainbow Bridge incident. Muroi is asked to return to work, and he ponders whether he can keep his promise to his former colleagues. As the investigation progresses, each of the children Muroi has taken in grows up.
