On the verge of exam season, Chisato Shoda takes her anxious son on a mother-and-son hot spring inn getaway to ease his stress. Arriving at a quiet, slightly run-down ryokan, Chisato tells her son to study before heading to the bath. He nods and begins working, but soon pleads, "Do that thing you always do." With a resigned smile, Chisato says, "Fine, but only after you finish your problems," then pulls down his pants, takes his already-hard cock into her mouth, and slowly starts sucking. Once he finishes, he can't hold back and begins touching her. Chisato gasps, "Me too," pulls him close, and they exchange deep, passionate kisses. The two desperately embrace, caressing each other's bodies until they climax. Sated, they head to the outdoor bath, washing each other affectionately, naturally sliding back into intimate touching and desire. Unseen, a ryokan employee records their actions, having noticed their relationship is far from ordinary and decided to spy. The next day, the employee appears before Chisato, holding up the video from last night with a sly smirk.