Hyoga Mamoru is the CEO of Three Star Books. She was born into a wealthy family and has never experienced money problems. While she is successful with her job, she is lonely and holds sadness over the deaths of her parents when she was a child. Hyoga Mamoru has close friend Ichinose Ryo. He is the only one who she can talk to about anything. Hyoga Mamoru also started Three Star Books with Ichinose Ryo and they still work together. Meanwhile, Hyoga Mamoru gets involved with Haruno Yu, who is much younger than her.

Haruno Yu is a vocational school student. He has a loving family, that includes his parents and a younger sister. His parents financial situation is not very good though. While studying, he works part-time to support himself. He then applies for an intern job at Three Star Books.