Shihori Enodo remarries at 36, suddenly becoming the mother to two teenage sons. However, her husband is abruptly transferred for work, leaving her alone with the boys. As the three live together, the eldest son falls ill. Despite her anxiety over her husband's absence, she dedicates herself to nursing him, driven by her sense of duty as a stepmother. Willing to accept anything for her son's sake, she eventually engages in a physical relationship with him. When the younger brother discovers this, he begins making the same demands of her. The complex dynamics within the household deepen further.