Chisato, a serious and kind female college student, finds herself surrounded by older men, sinking into a sea of pleasure. In this situation, so unlike her everyday life, her arousal steadily intensifies. Matching the intense stimulation from the older men, she reaches climax after climax, her ecstasy unrelenting. The scene unfolds as a continuous series of shocks. The story carefully depicts how she ended up in this situation and how she gradually surrendered completely to the overwhelming pleasure.