Ryou Shiranui/Arms/Abilities

Arms
Mk.23 MOD.0: The "Heckler & Koch MK 23" or "USSOCOM MARK 23" is a, semi-automatic, large-frame, pistol chambered in .45 ACP. It was designed specifically to be an offensive pistol and comes paired with a laser aiming module and suppressor however Shiranui uses his without the suppressor.

Knife: Butei High students, especially those in Assault, are required to carry a knife and gun with them at all times. It's unknown what type of knife Shiranui uses but he is very capable with it regardless.

Abilities
Marksmanship: To Shiranui, shooting someone was no more difficult than tossing a piece of rubbish into a bin. He is able to remain completely calm and hit his mark; earning him the nickname "Old Hand". Although he primarily uses his MARK 23 he seems to be proficient with several other types of weapons such as his fully automatic USAS-12 shotgun that he used during his first mission.

Close Quarters Combat (CQC): Shiranui learned CQC from his time in Assault and is capable of besting foes with only his bare hands. His proficiency is so highly esteemed that Kinji has gone off record saying that he would have trouble beating him in a close-quarters battle even while in Hysteria Mode. However, his fighting capabilities have not been showcased to date.

Stealth/Tracking: Shiranui has the ability to completely hide his presence which helps him when he's trailing a target. His tracking skills are so advanced that even other Butei can't sense him. This was shown in volume 12 when he managed to track down Kinji after he left Butei High and sneak onto the same train car as him without raising suspicion.