Midori Hinamori is the mother of Amu Hinamori and Ami Hinamori, and the wife of Tsumugu Hinamori. She works as an editor for the magazine Housewives' Knowledge, a job that reflects her practical and organized nature. Midori is responsible for choosing the clothing styles for both of her daughters, which directly influences Amu's outward appearance and contributes to the cool and spicy image that others perceive.

Her personality is characterized by a level-headed and understanding disposition, especially compared to her husband. She is more accepting of Amu's relationships with boys and shows a willingness to trust her daughter's judgment. In moments of crisis, such as when Amu is discovered with Ikuto in the house, Midori believes Amu and actively seeks to help, even going so far as to look for a place for Ikuto. She also offers cryptic but reassuring words to Amu, telling her that everyone believes in her, which underscores her role as a supportive and trusting parent.

Midori's motivations center on the well-being and happiness of her family. She balances her career with her domestic responsibilities and often acts as a mediator or source of calm wisdom within the Hinamori household. Her role in the story is primarily as a supporting character who provides emotional grounding and practical care for Amu, allowing the protagonist to navigate her own challenges with a stable home base.

Her key relationships are with her husband Tsumugu, from whom she differs in parenting style, and her daughters, especially Amu. She maintains a close and open bond with Amu, acting as a confidante when needed. While Midori does not possess any special abilities like the Guardian Characters, her influence is felt through her choices and her steady presence. Over the course of Shugo Chara!! Doki, she remains a consistent figure of maternal support, with her development shown in her increasing trust in Amu's independent decisions.