Karin to.

Oosawa Junpei is widely regarded as a hopeless underachiever. With failing grades, zero athletic ability, and an obsessive passion for astronomy, he hardly fits the mold of a romantic lead. Yet against all odds, he continues to pursue his longtime crush, Kido Karin, desperately searching for any opportunity to win her affection. His efforts are made infinitely more daunting by the existence of Karin’s twin brother—a flawless overachiever who excels in academics, boasts striking good looks, and plays in the Junior Japanese soccer league. Standing in the shadow of such perfection, Junpei’s chances seem virtually nonexistent. A sudden shift in fortune occurs when Karin unexpectedly invites Junpei to visit the planetarium with her. However, this rare moment of hope is shattered almost immediately. While observing through his telescope, Junpei is caught by Karin’s twin brother inadvertently peering into her room just as she is changing clothes. Rather than simply confronting him, the brother drags the terrified stargazer up to the school roof. There, waiting beneath the open sky, Junpei discovers something entirely inexplicable: a mysterious alchemy circle meticulously drawn across the rooftop, hinting that forces far stranger than teenage romance are about to unfold.