A woman with an attractive butt has moved in to the upstairs apartment. Her husband, who is much older than her, is also crazy about her. One day, a guy was looking at her butt on the stairs. However, as the wife was going upstairs, she stumbled and pressed the guy downstairs with her butt! He made her take care of him after he got injured! When the lustful guy approached the wife's butt, using his injury as an excuse...?