Haruko Kamio is Misuzu Kamio's aunt and foster mother. When Misuzu was younger, she was forced onto Haruko after her biological mother died and her father left her. Haruko loves Misuzu as her own child; however, she distances herself from Misuzu in the fear that if they became too close, it would hurt all the more if she gets taken away. Haruko enjoys drinking and riding her motorcycle which she often crashes into the garage after work. She also has many part-time jobs instead of one full-time job.
Haruko is first introduced when Misuzu brings Yukito home and asks if he can stay. Although distrustful at first, Haruko soon trusts him and forces him to drink with her. When Misuzu breaks down crying, Haruko explains to Yukito of her disease and Misuzu's past with her father. She also explains her fear of Misuzu getting taken away and says that she distances herself from Misuzu to not get attached.
When Yukito leaves and Misuzu's condition gets worse, Haruko decides to officially adopt Misuzu instead of living in fear and restricting their relationship. However when Misuzu's real father appears to take her with him, Haruko is sent into despair after finally allowing herself to hope for a family. After Misuzu rejects her father to stay with Haruko, she begins to act more like a mother and spend more time with Misuzu, but because of Misuzu's condition she isn't able to do much. One day, when Misuzu asks if they can go to the beach, Haruko happily accepts; however, when they get there, Misuzu dies in Haruko's arms, leaving her to cry at what they could have done now that they were a proper family.
