“I can’t keep up with Kanna’s sex drive every night. Why don’t you find another way to burn it off?” Her husband’s remark inspires her to join a gym. She throws herself into training, but the more she exercises, the hornier she gets. Then she meets Yuichi in a corner of the training room. While closely teaching the inexperienced young man how to use the equipment, she notices the bulge growing as he works out and cannot control her desire for him.