Ginko Murakami is a sixteen-year-old student at Seiryo High School and granddaughter of Ginji Murakami, a notorious inner society informant. She has assumed her grandfather's role as an information broker but confines her activities to managing his inherited online information network rather than expanding it. This work provides vital support to her childhood friend, Shinkuro Kurenai, whom she has known since kindergarten. Ginko locates information and new jobs for his troubleshooting, leveraging online databases and her unique position as the sole member of the high school press club. This role serves as both cover and private workspace.

Physically, Ginko sports short, chin-length hair and glasses. She is rarely without her laptop, essential for gathering information. Her leaner figure, compared to classmates, persists despite increased meal intake, a trait she dislikes. She habitually arrives early to eat snack buns for breakfast in the classroom.

Outwardly taciturn, dishonest, and gallant, Ginko is internally careful, thoughtful, and privately compassionate. Lacking athletic or self-defense skills, she relies on intellect and information networks for safety. She displays gentleness around animals, like her dog Ginkurou (named after herself and Shinkuro), and towards young children such as Murasaki Kuhouin, whom she assisted during a class inspection. Ginko harbors strong dislike for Benika Juzawa and the Hozuki clan, especially Yuno Hozuki, fearing for Shinkuro's safety in their world. This animosity prompts her to avoid sharing physical space with Yuno whenever possible.

Shinkuro remains central to Ginko's life. Beneath her reserved exterior lies deep sincerity and protectiveness rooted in their shared childhood. She is among the few aware of his traumatic past, including his family's loss. Ginko frequently urges him to abandon troubleshooting, fearing for his safety, and offers him work at her family's ramen shop, Fuumitei, hoping he will live and work with her instead. She has held romantic feelings for him since childhood, once dreaming of marrying him and running Fuumitei together. While less overt about her affection than others, she becomes visibly irritated when girls like Yuno approach him. In vulnerable moments, such as Shinkuro expressing love, she reciprocates sincerely; her feelings are portrayed more vividly in the manga than the novel.

Financially, Ginko maintains savings reportedly reaching eight figures in yen. Her daily life balances school, information brokering, and part-time work at Fuumitei, reflecting her practical drive for stability and desire to offer Shinkuro an alternative to dangerous work.