Out of concern for her father-in-law, who was left alone after the death of her mother-in-law, Rin decided to move into his home with her husband, Akira. While her husband is kind and caring toward his parent, he is also serious and meticulous, hating nothing more than having his daily routine disrupted. Naturally, there is no intimacy between her and her husband. One night, feeling a deep ache in her body, Rin is caught masturbating by her father-in-law. The next morning, as soon as her husband leaves for work, her father-in-law reveals his hidden desires and begins to devour Rin's body... At first, Rin resists, but her body gradually becomes honest with its pleasure.