[More than a sister... always a friend... less than a lover] For 10 years, she has been satisfying her brother's sexual needs with a strange love relationship that no one can tell anyone about. "It's not disgusting... you're my hero," says the sister, trying to comfort him as she watches his gloomy, childish appearance. One day, she accidentally sees his morning erection and he demands that she "stroke it off with your hand," and she can't refuse. From there, his demands escalate, and the moment they cross the line... the dirty room becomes their secret base...