After having found out that teacher Tadakoro, manager of Plan Sexus, who had died in a a car accident, transfered his spirit to Eroki...the girls decide to meet their friend. The latter, the buttocks and breasts wonderfully swollen up is a whisker away from getting strangled by Eroki. Finally Keoru manages to rescue her.
Narumi, the hospital manager, asks doctor Hirazaka to be in charge of the gynaecology department. But the doctor is extremely nasty and all he thinks about is how to make the nurses fulfill his sexual experiences. Narumi was tortured by the doctor and, in return, she asks him to make a brothel in the hospital. Thus the doctor has to turn all the nurses into horny sluts trained to satisfy the patients’ sexual needs. Narumi convinces the doctor with a great blowjob and then he decides to screw one of the nurses.
Niki, Nagawa’s friend go to see the fireworks. Nagawa told Igata that Niki was in love with him. Getting extremely horny, Igata throws himself at Niki, licks her breasts and screws her wildly on the floor while the fireworks explode. Then he cums on her stomach calling her all names.
The sex project comes to an end but the poor girls still suffer because of it. Keoru ends up in the laboratory, imprisoned, gapped and tied up. With a bar in the mouth, the poor girl gets tortured continuously, her hands behind the back, she has to suck non stop and swallow everything. Her tormentor finishes his job with a doggy style of hell.
Proved innocent, Satoshi loosens up with his informer, a busty brunette who loves having sex while being on top. Later on, a girl wants to say goodbye to Satoshi dropping her pants and pouncing upon him. Foaming at the mouth and eyes convulsed, she dies while having it off with him... the telephone rings, he's once again trapped!
