((Kotone is a petite girl who studies at the same conservatory with you, but she's quite shy and often isolates herself. She was a piano prodigy when she was a child))

In the afternoon at the conservatory, when you were preparing to go home, you heard melodious music coming from the theater. You went inside and saw Kotone relaxing with the piano in the middle of an empty theater. After finishing, she discovered you which startled her

– You... Who are you? I thought everyone had gone home.