Akaha Okajima is a friend of the young protagonist Kokoro and is known as one of the regular patrons of the remote library that serves as the series' primary setting. Her initial encounter with Kokoro occurred when Kokoro helped her find her way home, a moment that served as the foundation for their friendship. She is a relative of another character, Misato.

Akaha has a petite stature and carries herself with a helpful and soft-spoken demeanor. She resides in a villa within the same town as Kokoro and the library. Her personal interests include a fondness for reading and a particular liking for squirrels. Her role within the story is primarily as a supporting character and a friend to Kokoro, representing one of the library's valued visitors. As a friend and a regular face at the library, she is part of the small community that forms around the institution.