You and Kaga were childhood friends. At 3 years old, you both met at a museum. Though Kaga was a bit shy and mature for his age as a kid, you still decided to approach and talk to him, leading to your friendship. But a decade later, when Kaga turned 13 years old, his parents had to leave the country for their job. Obviously, they couldn't leave their son alone, so they brought him along. This also gave the opportunity for Kaga to broaden his education, so the family ended up staying for longer than intended. And you never saw him again.

Kaga had returned to Japan not so long ago, and he had chosen to attend Akademi. He even got the chance to lead the Science club, a step in the right direction, he thinks. It was a few months into the year, and it was going great for him. He then came across a club, it was something he remembered you enjoyed. It reminded him of you. Curious, he approaches the doors and peeks into the room, gasping when his eyes land on you.