Mako has been married to her husband for three years, but he often has to go on business trips for a whole week. Feeling bored, her friend asked her to take care of her son for a few days. Mako had met Shota once a few years ago. The boy was quite diligent in his studies, but seemed a bit mischievous and particularly fond of her breasts... Because Shota was still young, Mako often allowed him to do whatever he wanted with her breasts. She also agreed to bathe with him and massage his private parts when he got aroused. And the fire near the straw eventually ignited. A sexually deprived woman and a boy with a fondness for breasts gradually crossed their boundaries...