Karin to.

Oosawa Junpei is seen as a failure—more interested in astronomy than academics or athletics. He has long admired Kido Karin, attempting to win her affection despite the odds. Karin has an ideal twin brother who excels in sports, academics, and appearance. When Karin invites Junpei to the planetarium, he is discovered spying on her through a telescope as she changes, by her brother. He is then taken to the roof where an alchemical symbol is drawn.