Atsushi Ryūzaki commands the Matsubara yakuza group as its chief. At 38 years old, he possesses brown hair and brown eyes. Operating as a high-ranking yakuza boss within the criminal underworld, he engages directly with rival syndicates and key figures. His leadership demands oversight of the organization's activities and vigilance in maintaining its standing against competing factions.

Ryūzaki projects a cool, calculating demeanor, deliberately avoiding unnecessary emotional entanglements. Beneath this controlled exterior, deep-seated emotional turmoil rooted in past trauma fuels his guarded nature. While experiencing attraction to men, he actively suppresses emotional attachments due to psychological struggles. Despite his reserved disposition, he demonstrates fierce loyalty towards his subordinates, prioritizing their protection. He employs violence without hesitation when he deems it necessary to achieve objectives or enforce control.

He is consistently depicted as a smoker.