It was just a joke. One of my students, Sato, who had nothing in particular he wanted to do and was undecided about his future, asked me to go on a date with him when he graduated. I thought, if that would motivate him... I made the promise without thinking. However, from that day on, Sato started to work hard like a new boy, and I couldn't back out... It would be okay if it was just once, and my husband wouldn't find out. So I decided to go on a date with Sato, who had graduated without a hitch, as promised, but I never expected it to turn out like that.