One month ago, Yumi and her husband began living with her mother-in-law to save money for a home of their own. However, Yumi has one complaint: she can clearly hear her husband's nightly activities in their bedroom. Unable to suppress her arousal, she resorts to masturbation, yet her body craves being taken. Soon, she realizes that her stepson Ataru harbors feelings deeper than mere familial affection, and Yumi begins to deliberately stir his lustful desires. But as Ataru hesitates to take the final step, Yumi's body draws closer to its breaking point. The story unfolds as their suppressed passions inch toward fulfillment.