Sana, who works as a case worker, decides to give advice to her neighbor Oki, who is receiving welfare due to Kokoro illness. However, for Oki, whose wife has run away, Sana is the closest and most attractive woman. Unable to contain himself, he forcibly pushes her down as an outlet for his overflowing sexual desire... At first Sana resists, but once her body is wet from the powerful and rough sex, she accepts the erect penis and before she knows it, she begins to entwine her tongue with it. However, such a secret cannot continue forever...