Kyonyû jukujo: Torokeru tehodoki.

Makoto, a company employee, reunites with his middle school crush, Ms. Kaori, in the same apartment building. Kaori had lost her husband in an accident and had quit her teaching job. The two eventually become physically intimate. Kaori scolds Makoto for his one-sided and rough treatment of women, teaching him through her own experience. Makoto becomes captivated by the gentle guidance he discovers from this mature woman…