During her student days, Akari had a boyfriend with whom she had outstanding sexual chemistry. The chemistry was so intense that she could hardly think of anything else. Thinking she would be ruined if she continued this way, she made the bold decision to break up. However, even now, as she is about to marry a fiancé she met after entering the workforce, the memory of her ex-boyfriend remains deeply etched in her mind. Then, she receives an invitation to a school reunion. Fearing a reunion with her ex, she tried to send a notice of absence, but her fiancé arbitrarily decided she would attend. Forced to attend the reunion, the situation she feared came to pass. Upon reuniting with her ex, just a touch on her shoulder brings back memories of the days when she was driven crazy by sex. Swept away by the rising impulse, she tells herself, "Just once..." and goes to a hotel, but she forgets all about the fiancé waiting at home and drowns in sex with her ex, who knows every single one of her erogenous zones.