Orie is Oono Haruka's much older sister. She used to attend Fujigaya Girls' Academy when she was younger though she was not the inspiration for Haruka's later enrolment. She was in the same year as Yamashina Hinako and both of them were close friends. Orie had a crush on Sugimoto Shinako (her upperclassman) and when she caught Hinako with a love letter, she dejectedly assumed it was for Shinako, who was admired by nearly the entire student body. She was shocked to learn that the true addressee of Hinako's letter was actually herself. Orie felt guilty after Hinako confessed to her because she thought that her newfound feelings for her best friend were a direct result of the confession. She later came to realise that she truly loved Hinako, and initiated their first kiss, much to Hinako's surprise. Orie even burst out into tears at the thought of Hinako leaving and forgetting about her when it was time for them to graduate. Orie lives on her own now in an apartment. Hinako often keeps her company, keeping the promise they made many years ago about always being together.
They eventually come out to their parents, as chapter 39 suggests.