Due to work, Mitsuru has been living alone in Tokyo for three years. On một visit to the doctor, he discovered that he had a tumor in his body. Thinking he didn't have long to live, he took his beloved mother on a trip to enjoy some joyful days before he died. They both went to a hot spring hotel. Mitsuru had long secretly loved his mother. So when his mother got drunk and revealed her beautiful panties in front of him, he couldn't help but touch and explore her body. His mother woke up and stopped him; Mitsuru then told her that he didn't have long to live. Out of concern for her son and wanting him to fight against his illness, Aoi agreed to support him. Upon returning, Mitsuru went for a follow-up examination. It turned out that it was just a benign tumor, and due to the doctor's serious expression, he had misunderstood. After this incident, the relationship between the mother and son improved even more. Although there was no longer any danger to life, Aoi still agreed to let Mitsuru be intimate with her, even though she knew this was wrong...