Ryo, a newlywed, lives with her mother-in-law, Sayoko, because her husband is away from home. The two of them lived on good terms, but Sayoko began to have special feelings for Ryo. One day, Ryo can't stand loneliness and starts masturbating in the bedroom. Sayoko peeks at it and indulges herself in masturbation. The next day, Sayoko's distorted affection for Ryo, who can no longer control her emotions, is directed at Ryo.
