Ushio Keiko was Ushio Hinomaru's mother. She used to be his greatest fan while in elementary school, but due to her poor health, passed away while he was in Junior High.
She was relatively petite and slim, due to her poor health.
In stark contrast to her son, Keiko used humor to put up a front, constantly joking around and at times, according to her, annoying him. However, deep inside, she was always concerned about her child, as she knew how her way of being and her health affected him in such a way that he closed off to the others.
She also felt she was a failure of a mother, particularly because she felt it was her fault that Hinomaru had been born short, as well as not having many good traits, which also made her somewhat dependent on her husband when he was alive.
Quite unlike her son, who's level-headed and a good student, Keiko hated studying and would often get in trouble at school due to her rambunctious behavior. She eventually dropped out and eloped with her husband, moving from place to place, along with little Hinomaru once he was born. This nomadic lifestyle led to her son's odd, somewhat old-fashioned speech patterns.
However, her poor health caught up to her, which led to her going back to her parents' house after her husband's death, even knowing she wasn't long for this world, and recorded a video for Hinomaru's eventual bride, using her humorous front to hide her fear of dying. She eventually passed away at the age of 34, while her son was in Junior High and he was in a tournament, which didn't allow him to be there in her final moments, something he deeply regrets and led to a fear of abandonment in the young boy.
- She was voiced by Watanabe Akeno
- She hated studying, but she loved talking to other people.