Kagamiya Rin

Mitsuki's kouhai. She is often seen reading books in the library or doing work in the student council room. Rin has a brash and aburpt personality, though she acts sweetly around those she trusts. She's very close to Shigehisa's little sister, Chitose.

Spoiler

Due to a heart disease, Rin has spent the majority of her life in a hospital bed, and has only recently been discharged, thus she is experiencing many things for the first time. She's also a writer under the pen name of "Yagami Karin".