Based on the doujin erotic game by Crimson.

The Crimson Girls protect women from train molesters. Mitsu, one of the two members, caught the attention of a unique man who could make a woman orgasm with just a touch. He and some of his friends trap Mitsu on the train and brought her to the hotel where she was tortured and had her virginity taken. Now that one of the Crimson Girls has succumbed to his will, his next target is Saki...