TV-Series
Description
Soichiro Hinamura, nicknamed "Yondaime" (The Fourth), leads the Hirasaka Group, a NEET-affiliated yakuza organization in Shibuya he co-founded. This group assists the NEET Detective Team, especially upon Alice's request.

He possesses average height, white spiky hair, and brown eyes. His typical attire consists of dark tank tops and long dark pants, with a distinctive purple butterfly tattoo—the group's symbol—visible on his left upper arm or shoulder. Hinamura maintains an impersonal and brusque attitude toward everyone, yet unexpectedly repairs Alice's damaged stuffed bears when asked.

His backstory involves founding the group with Renji Hirasaka and roommate Hisan. The butterfly emblem, designed by Renji, remained unfinished. After Hisan's supposed death, Renji broke their sworn brotherhood oath, causing conflict. This event shaped Hinamura's leadership and commitment to the group. He evolved from an association with violence toward a neighborhood-friendly approach, opposing activities like drug-dealing in their territory but enforcing boundaries harshly when necessary.

He shares a sworn brotherhood with Narumi Fujishima, mentoring him and using nicknames like "Gardening boy." Narumi serves as Hinamura's trusted confidant and unofficial second-in-command. Hinamura respects Alice, frequently hires her for investigations, and tolerates her calling him "Fourth" despite disliking it. Functionally, he acts as a strategic ally to the NEET Detective Team, critically intervening in crises like drug threats and providing logistical or physical support during investigations. His leadership blends pragmatism with responsibility for his territory and allies.

A recurring detail is his technological ineptitude. His subordinates' inability to handle basic computer tasks forces heavy reliance on Narumi for simple fixes like virus scans, leading them to jokingly dub Narumi "God Hand."