At a glamorous class reunion, Matsui Hinako is reunited with her "former master." During her student days, she was thoroughly trained as a secret sex slave. Convinced that she is who she is today thanks to her master, the moment they reunite, she regains her sense of being a "tool." In the shadows of the party venue, with her husband nearby, she bends to her master's knees and sucks his cock as he commands. Their former master-slave relationship is revived, and she is once again trapped in a cage of pleasure in this NTR story of despair and ecstasy.