Minako was depressed after her husband died three years ago, but after she started attending a certain culture school, her smile returned to her expression, and her son Kenji felt relieved. One day, Kenji finds out. The culture school that Minako attended is a culture school that teaches housewives "bondage". Kenji, who saw her mother's "no hail" and the "rope marks" left on her body, impulsively roped Minako.
