Ryou Shiranui (不知火 亮 Shiranui Ryou) is a bright handsome popular guy, with a Butei level of A. Even though there are different aspects involved in an A-ranking, his integration capacity is high. Barehanded, dagger handling or shooting aspects can all be relied on. The reliability of his gun is very high, a Mk.23 MOD.0 with an installed laser aiming lens. He is also a rare polite person in Butei High. Even though he is very popular with girls, he never had a girlfriend before. He is Kinji Tohyama’s and Gouki Mutou’s friend.
Shiranui's actual family background and his other kinds of history are not actually mentioned except once. During the events of Volume 5, it was revealed that Shiranui seems to have experience in playing the game of soccer. He ended being the mid-fielder for the Butei High team because of this.
Shiranui has been mentioned to be polite, which seems to be rare to other students in his school. Disregarding this, Shiranui is a very caring friend and even helped Kinji when he needed it, despite Kinji not asking him for assistance. Same goes for Mutou.
However, Shiranui has been known to poke fun at Kinji when it comes to relationships with girls. Most of his manners fly out the window when teasing him, even collaborating with Mutou to send an embarrassing text message to Aria through Kinji's cellphone.
Shiranui is very capable in his department: Assault. He is an A-Rank Butei Assault member. He seems to be very capable in pistol fights and in CQC (Close Quarters Combat) with both a dagger and his own fists. However, his fighting capabilities have not been showcased to date.