Eimi, a teacher, married her colleague this spring. Aoi, a student who secretly has feelings for her, who is still teaching, is unable to concentrate on his studies and his grades are worsening. Eimi, unable to see him like this, calls Aoi to her home and decides to teach her some lessons, but luckily or unfortunately, Eimi's husband is away for four days leading a club activity. A once-in-a-lifetime opportunity that Aoi never expected has arrived.