Accompanying his wife, Mayu, on her trip back to her parents' place for the birth of their child, husband Kazuyoshi finds himself unable to sleep due to the allure of his sister-in-law, Meguri, whom he hasn't seen in a while since Mayu's pregnancy. One night, he accidentally catches her in the act of pleasuring herself. The next morning, Kazuyoshi is lost in thought, remembering her lewd behavior. Seeing this, Meguri, unable to contain her daily frustrations and desires, instinctively pounces on his cock…
