Mai Hanagari is an innocent girl with a lovely, innocent smile. She is well-liked by everyone, well-behaved, and has no flaws... but she is transformed by a corrupt PE teacher who has been after her for a while. When she goes into the PE teacher's house to get something she forgot, she is raped on the spot without question. No matter how much she resists, he doesn't let up on her and continues to violate her. Then a delinquent classmate comes and rapes her, thinking he'll help her, and ends up fucking her all the way to her precious asshole. This awakens Mai to her anal desires, and she begins to go off the rails, as if she's going down a dark path of her own accord...