One day, Aoi and her husband Daichi are suddenly held captive by a mysterious man. Also present are Sagawa, a man from a construction company with whom the two have a relationship, Machida, their neighbor, and Terudai, a student whom Aoi teaches. The five of them cannot hide their shock... Just then, a timer appears on the electronic bulletin board along with a voice saying, "You will now all have sex," and begins the countdown. After much conflict, Aoi and Daichi end up having sex in front of the three. The two are supposed to be able to leave the room, but Sagawa gets in the way, and Aoi is left behind in the cage...