Emi, a teacher, married a colleague this spring. Aoi, a student who secretly has feelings for her, who continues to teach, is not concentrating on his studies and his grades are declining. Unable to bear seeing him like that, Emi invites Aoi to her house to help him with his studies... but for better or worse, Emi's husband is away for four days leading a club activity. This is the golden opportunity that Aoi never expected.