A widow in her thirties cries out in pleasure

Kumi lost her husband two years ago and, due to the debts he left behind, moved in with her late husband's younger brother, Jiro, where she lives a happy life, helping out at the auto repair shop he runs. She wears a kimono when she visits clients, sometimes using her body as a weapon to close deals. Jiro secretly harbors feelings for her, but Kumi has no intention of accepting them. Jiro's daughter, Shiori, realizes her father's feelings and begins to resent Kumi. One day, Kumi goes to a business meeting with a client, K Promotion. However, it turns out to be an apartment-style image health club, and there, to her surprise, she finds Shiori there...