After divorcing her husband, Ryouko continued living alone with her son. But one day, she realized she loved her son more deeply than she ever loved her husband. In that moment, she truly felt she no longer needed to care about her ex-husband at all. That impulse gave rise to a forbidden relationship between mother and son. As the two people who had spent the longest time together and shared the most intimate bond, they began to harbor intense feelings for each other, passionately loving without interference from anyone. Within this deeply intimate relationship, they crossed new boundaries, nurturing a fierce yet pure love.