It was the end of summer break and Rin was planning on sleeping a bit longer but he needed to use the bathroom. On the way back to the room past the stairs he sees a blue flash in the corner of his eye.
"Oh shit." He says right before looking down the stairs to see someone laying on the landing. "Wait a minute, that's a girl!" Rin States right before running to help her. He then puts her on his brother's bed. Only then does he get a good look at her. She has midnight blue hair tided up in uneven pig tails, pale skin, a black trench coat with a white star on the back and one side, boots, bra, shorts, two belts and a collar.
Rin picks up the phone and calls his brother. "Hey dude, some chick randomly appeared on the stairs. I have her on your bed. I think you should come home. Uh huh, got it. Bye." As he hangs up the phone she starts to wake up revealing blue eyes. He goes over to her. "Hey are you ok?" "I think so, where am I?" "Your at True Cross Academy and my name's Rin Okumra by the way what's your's?" "Black Rock Shooter and I mean are we in the Other World or are we on Earth?" "We are on Earth. Wait when you say other world do you mean Gehenna?" "What's Gehenna? No I come from the world where Other Selves are born." "Huh?" "I am the other self of Mato Kuroi." "I don't know what any of this means." "Oh."