Rina

The older sister, Runa, has red eyes and a polite manner. The younger sister, Rina, is always active and noisy.

The two are always together, no matter what the occasion. For some reason, they seem to feel closer than necessary to the protagonist, whom they have never met before.

It seems that there is a secret between Rina and the main character. She knows that the main character and the idol Maria are living together, and uses this as an excuse to get close to the main character.