Left alone when his wife goes on a trip, the husband's marriage slowly grows cold. Amidst this loneliness, he finds himself drawn to his wife's older sister, Airi. If only I had met her before my sister-in-law... he thinks, yet he can't resist her advances. Whispering sweet nothings in his ear, Airi slowly breaks down his resolve, and day or night, morning or evening, in his wife's absence, he becomes trapped in a passionate affair with her. Again and again they climax inside her, until his mind and body are pushed to the limit. [Premium Exclusive Release, First Production]