A rumor was circulating about an after-school devil.
Its true identity was students whose forbidden impulse is awaken. ""From a best friend to a best friend"". The desire was infectious.
There is only one way to be free from it. That is to have a sexual intercourse and inject the seed of desire into the vagina.
The want that comes from deep in the body. The ""new instinct"" arises. That is something that erects under the skirt. Its need for pleasure targets her close friends...!!
Senior and junior students and best friends... all of the girls are captured and penetrated. And they wander in the school as the next after-school devil. The curse is all over the school. Most of the students experienced it by then.
The order of the school was maintained only by their feeling of shame. Their sin was regarded as a rumor and their daily life continued as if nothing has happened...