Shinji returns from an overseas business trip and moves into his brother's house. His sister-in-law, Aki, is incredibly airheaded and clumsy! He spends his days tossed around by her unconscious temptations, from her panties being in full view to her barging into the bath. One night, while Aki is dead drunk, she demands him to "rub me more," leading to forbidden sex right next to his brother! The next morning, she has no memory of it, but her body cannot forget the pleasure, and she unconsciously begins to seek him out for night sex!
