The Caged Flower (2013)

Kaisu, an office employee, who was raped-by-mother's-boyfriend many times and "S" a boy, who is sexually abused by his young mother meet in a chat room on the internet. It starts with some innocent flirting, but soon they end up in a master-slave relationship, where the boy gives the assignments and the girl performs them. Some time later they meet each other in real life and the games are no longer so innocent.