Mafuyu Shinoki is a supporting character in the anime Mahou Shoujo Nante Mouiidesukara, specifically appearing in its second season. A high school student around fifteen to sixteen years old, Mafuyu is one grade above the series' main protagonists, Yuzuka Hanami and Chiya Sakagami. Her given name, Mafuyu, translates to midwinter, a thematic link to her magical girl attire. She works at her grandfather's cafe, demonstrating a connection to her family and a sense of responsibility.

In terms of personality, Mafuyu is characterized as a friendly and approachable young woman. She carries herself with a general sense of composure but is not without her insecurities, notably feeling a degree of embarrassment regarding her magical girl transformation outfit. As an older and more experienced magical girl, she develops a mentorship dynamic with Yuzuka and Chiya. Her motivation is to be a figure worthy of their admiration, aspiring to be looked up to by the younger protagonists. This aspect of her character is particularly evident in an episode from the second season.

Mafuyu became a magical girl after forming a contract with Pochi, a small, dog-like magical creature who serves as her constant companion and the source of her transformation powers. Her magical girl costume is themed after Santa Claus. Her primary magical ability allows her to manipulate the size of her bag, expanding it or shrinking it as needed. Within the story's universe, magical girls have a mandatory retirement age, and Mafuyu is nearing this limit. Chiya Sakagami is suggested as a potential candidate to take her place as a magical girl after her retirement.

Regarding her key relationships, Mafuyu quickly befriends Yuzuka Hanami upon discovering that Yuzuka is also a magical girl. Her relationship with Chiya Sakagami develops more gradually, often during study sessions held at her family's cafe. She also interacts with Daiya, a younger character, in these same social settings. While generally open, Mafuyu maintains some level of secrecy about her magical girl identity. Her surname has variant spellings in different sources, appearing as both Shinoki and Shinogi.