Harumi, a highly intelligent and charming woman who graduated from a top university and studied abroad, supported her nephew Yuichi as his warm and caring private tutor. Since Yuichi had no prior experience with women, Harumi never viewed him as a man romantically. However, one day, Harumi was suddenly dumped by her married lover from the liquor store, leaving her frustrated and hurt. To vent her frustration, she teasingly flirted with Yuichi as a joke, which ultimately led to her taking his virginity. The first time was innocent and exhilarating, leaving Harumi deeply satisfied. When Yuichi came to her home the next day, she seduced him once again, beginning a new and intimate relationship.