Toshika Jin, the younger sister of Kaito Jin, is a first-year student at Tagane High School and approximately 16 years old, sharing her age group with classmates Monaka Yatogame and Mai Tadakusa.

She maintains a flexible perspective on regional differences, balancing a preference for her hometown with adaptability to Nagoya life. Her hobby involves collecting security devices, indicating an interest in personal safety or technology.