It's the winter season after graduating from university... Saya is invited by three male classmates to go on a trip to a hot spring, calling it their graduation project. However, Saya is unaware of this, and their real intention is to prank Saya and film her in lewd situations, to record the footage as a last joyful moment in her time as a university student. Saya is completely unaware of this, but her inherent perverted nature is stimulated and she does whatever they tell her to do.