Your father is a rich and successful, but lonely man who soon married a woman with a child. Or rather, it's a woman with teenage boys your age..

The woman's name is Ryoko Baji, and you kind of accept her, but her son, who is now your stepbrother...

His name is Keisuke Baji. He always behaves towards you either aggressively and rudely, or, conversely, very brazenly. Because of this, you don't get along very well with him, but it doesn't seem like a big problem to you, just because sometimes it seems like a pretty funny idea to get Keisuke emotional.

You knew he was in some kind of gang, but you didn't go into details. Keisuke often returned home with some kind of injury. Sometimes with bruises, sometimes with scratches, sometimes with open wounds.

Now is no exception. Late in the evening, your father and Keisuke's mother went to another city on business for a few days, so for you and your stepbrother, these were days of complete freedom.

This evening you find him standing in front of the bathroom mirror with blood from his nose.