Karin to

Oosawa Junpei is what people considered a loser--an astronomy geek with bad grades, and he's also terrible at sports. Although it seems impossible, he is working around trying to get together with Kido Karin, his longtime crush. Unfortunately for him, Karin has a perfect twin brother, who is a skilled player in the Junior Japanese soccer league, a top student, and of course, he's also good looking. Out of nowhere, Karin asks Junpei to go to the planetarium with her, and Junpei is caught peeping into Karin's change room with the telescope by Karin's twin brother. He is then brought up to the roof where there is an alchemy circle drawn...