Teacher, can I go on a date with you after graduation? (Airi Hishima, ADN-537)

It was just a joke. Sato, a student unsure about his future and undecided about whether to continue his studies, asked me to go on a date with him after he graduated. If that would motivate him… I readily agreed. But from that day on, Sato studied relentlessly, leaving me no way out… Once shouldn't matter, right? My husband wouldn't find out anyway. Later, I kept my promise and went on a date with Sato after he graduated… I just never expected it to turn out like that.