One of the hentai mini masterpieces. The boy witnessed his mother being touched by angry men on the train, and she loved it. He grew up to be the same evil man who gently pushes girls to orgasm in the train jostle. Gradually, he gets regular customers and fans who are just voyeurs like him. As it turned out, he is not alone, but their whole community. They are run by a veteran uncle who has devoted his entire life to it. But there are pitfalls to this kind of hand-holding, of course, in the form of a policewoman. Beautifully drawn, not a bad ending, what more can I say...