A man who went to visit a coworker's house suddenly witnessed his friend's mother, Reiko, flashing her underwear. Unlike his mother's worn-out underwear that had no sex appeal, Reiko's underwear was still in full swing and was ready to seduce the man, and the man's eyes were glued to hers. The man was unable to contain his excitement at the provocative flash of Reiko's underwear, which was giving off seductive pheromones, and writhed in ecstasy...Reiko, noticing his heated gaze, changed into even more seductive, risqué and erotic underwear, teasing and provoking the young man's innocent lower body...