Hitoshi Sugoroku is the 22-year-old younger brother of Hajime Sugoroku, a supervising officer at Nanba Prison. He is Japanese with AB blood type. His appearance is notably effeminate, featuring long, flowing light blonde hair that reaches past his waist, often tied into multiple sections with white ribbons, including three tied-back portions and side tails. This look, combined with his initial attire of a white Lolita-style dress, white heels, and a ribboned headdress, frequently causes confusion about his gender. His eye color is blue in the manga and green in anime adaptations. He also wears pink nail polish.

After joining Nanba Prison as a guard, initially working in Building 13 alongside his brother Hajime, he transfers to Building 4 as a low-ranking officer. His standard guard uniform is modified, featuring a long white skirt-like design and high heels instead of trousers. His personality presents a sharp contrast to his brother's stern and violent demeanor. The kanji for "Hitoshi" translates to "benevolence," reflecting his calmer, gentler disposition. He engages in hobbies such as preparing bento meals. Despite his reserved nature, he maintains a familial bond with Hajime, evidenced during an on-screen visit where Hajime corrects inmates mistaking Hitoshi for female, revealing Hajime's protective yet exasperated attitude. His role remains secondary, primarily emphasizing the contrast with his brother within the prison hierarchy.