Though they've been married for several years, the Kazama couple has not been blessed with children. Their nighttime activities have been getting less and less every day, in proportion to the husband's sagging sexual desires. One day, while chatting with the mother of the Koda family next door, Riri, the topic of an extremely powerful erectile dysfunction drug that is not available in Japan comes up. Yumi receives a small amount from Riri, who has already bought it, and plans to try it out that night. However, she accidentally gives the erectile dysfunction drug to Atsushi, the son of the Koda family, by mistake, thinking it is an stomach medicine...