Yura has been married for two months to a man with a child from a previous marriage. Although her relationship with her husband is good, she is worried about not being able to build a relationship with her stepson, Tomoya. One day, Tomoya, who has an extremely strong libido, asks her to help him masturbate... Yura is so happy to be called a mother for the first time that she helps her son release his frustrations as a mother. However, Tomoya is not satisfied with just one ejaculation, so he asks her for help again and again whenever he gets the chance. At first, Yura is unable to refuse and goes along with it, but before she knows it, she is the one to ask for help...