When Mina was 20, the man she was dating had a wife and children. When Mina got pregnant with his child, he asked her to have an abortion, but Mina refused and disappeared from his life, giving birth to Hiroaki alone. As she raised him as a single mother, every time she saw her son growing more like his father, she would remember their past love. Eventually, they crossed the line, and from then on, they spent every night together. When Hiroaki turned 20, Mina invited him on a hot spring trip to commemorate the occasion. Mina began to wonder if it was alright to continue their physical relationship…
