Sho Hinakawa is an Enforcer in Division 1 of the Public Safety Bureau's Criminal Investigation Department, designated Hound 4. He possesses gray eyes and messy red hair that usually obscures his left eye. Standing 175 cm tall and weighing 55 kg, his eyesight measures 0.7 in the left eye and 0.9 in the right. His bureau uniform is a dark suit, white shirt, and black tie, featuring bright purple lining on the rolled-up sleeves; during field operations, he adds a light brown hooded jacket secured with three frog closures. He can run 50 meters in 10.3 seconds.

Born December 26, 2094, in Tokyo's Nakano district, Hinakawa experiences severe depression requiring daily medication. He consumes soft drugs and vitamin supplements mixed into his food, such as supplement kake gohan, but his condition does not affect his work performance. He sleeps only 2-3 hours per night. Socially introverted and shy, he speaks rarely and avoids prolonged interaction, frequently using the phrase "Daijoubu".

Hinakawa leverages specialized expertise in holography and pharmacology, drawing on prior experience as a holography designer and drug recycler. This allows him to detect holographic disguises others miss and distinguish pharmaceuticals. He is technically proficient in VR hockey and card games. His hobbies include drug distinguishing and collecting items displayed on his room's built-in shelves, which he favors. He dislikes cannabis.

He shares a significant bond with Inspector Akane Tsunemori, addressing her as "big sister" and feeling motivated to protect her, a commitment maintained even against bureau opposition. Sibyl System assessments rate his compatibility as A+ with Kazumichi Irie and D- with Arata Shindo. He enjoys encouraging narratives like "Speed" by Ishimaru Genshou and "Passing Through the Middle of Eternity" by Nakajima Ramo, and desires a buckle from the Transformation Hero series. His personal motto centers on protecting Tsunemori.