Miko Shibuya is the mother of Yuuri Shibuya and his younger brother Shouri, and the wife of Shouma Shibuya. She was born and raised in Tokyo, Japan, and met her husband at a party, marrying him shortly after. During her university years at Ferris University in Yokohama, she was a member of the fencing club and competed in the Universiade, earning the nickname Hama no Jennifer. She sometimes refers to herself as Jennifer, a name suggested by a computer fortune-telling program.

Miko is an energetic and cheerful woman who often speaks at a rapid pace. She is easily excitable and tends to accept surprising news with little hesitation, such as learning that her husband is a Mazoku or that her son has become engaged to a demon noble. She is a devoted wife and mother, frequently found cooking or cleaning after her family, and always available to talk and care for them. Despite her upbeat demeanor, she harbors a lingering disappointment that neither of her sons was born with wings, a trait she had hoped for. As a young mother, she dressed Yuuri in girls’ clothing because she had wanted a daughter.

Her role in the story is primarily that of a supportive and occasionally humorous presence on Earth. She offers Yuuri unusual advice that sometimes proves surprisingly helpful in his adventures in Shin Makoku. Although she is a human with no magical abilities, she is a capable fighter, having trained in fencing and combat sports. Her key relationships center on her family: she is deeply involved in her sons’ lives and maintains a warm, if at times bewildering, household. Miko does not undergo significant personal development over the course of the series, remaining a consistently loving and eccentric maternal figure.