Son Hiroaki enrolled in a university in Tokyo, while his mother, Jun, remarried a man she met at work who had a child from a previous relationship. They began living separate lives under different surnames, and as their emotional bond as mother and child weakened, loneliness gradually led them into a physical relationship. Every year since her first husband was alive, they had made it a tradition to visit the rapeseed flower fields in Boso, a custom they continued together. This year, they traveled to the flower fields as usual, but afterward, Jun decided to abandon her life with her new husband and return to her son.