Matsuri Yoshioka is a side character in the story of Shōjo Sect: Innocent Lovers. She is a young woman with short orange hair and purple eyes. Unlike most of the other characters who attend Kagome Academy, Matsuri is a student at a different school. She is portrayed as deeply affectionate and somewhat playful in her approach to romance. Her primary motivation is her love for Kirin Suwabe, a key supporting character in the main narrative. Matsuri's desire to be close to Kirin leads her to feign illness, claiming to have mumps, in order to spend a day alone with Kirin under the pretense of being examined. This event occurs during the second episode of the OVA, where Kirin plays doctor for her.

Matsuri's role in the story is that of a love interest and partner for Kirin. Her relationship with Kirin is a significant romantic subplot, showing that Kirin, who is also involved in the larger dynamic with the main protagonists Shinobu Handa and Momoko Naitou, has an exclusive bond with Matsuri. The two eventually enter a committed relationship. Matsuri is not a student at the same school as the main characters, which sets her apart and gives her a distinct position among the cast. Her development is limited to this romantic arc, but it highlights her willingness to take initiative in pursuing the person she cares for. Notably, she does not display any special abilities beyond the ordinary, and her characterization revolves around her devotion and the lengths she goes to for closeness.