Hawk-Eyed Shu was once an incredibly talented military sniper. After he was discharged from the Japanese army, he had difficulty finding employment and eventually turned to working as an assassin for an unspecified Tojo Clan family. Unfortunately for him, he eventually failed at a job where he had to shoot in between two buildings and wound up getting expelled from the family he worked for.
Due to this failed job, Shu started becoming anxious whenever he found himself in tight places and needs to stay in wide open spaces to prevent panic attacks.
Desperate for income, Shu eventually joined the Reapers, putting his skills as a sniper to work against the yakuza.
After he joins forces with Ibuki and the Honest Living Association, Kiryu is sent to find Hawk-Eyed Shu and convince them to leave the Reapers.
Using information from a musician who hangs out in Taihei Boulevard, Kiryu tracks down Shu to his favorite relaxation spot on the rooftop of Millenium Tower. When approached, Shu initially believes that Kiryu is just another person looking to take in the view from the top of the tower. However, as soon as Kiryu reveals that he knows who he is, Shu draws a shotgun and attacks him. Despite his armament advantage, Kiryu manages to defeat Shu in battle. Shu is initially skeptical about joining the HLA, since he'd already sought out their help before and had failed to integrate into civilian life, but Kiryu manages to convince him to try again and to perhaps get some therapy for his claustrophobia.
In recompense for helping Shu leave the Reapers, Kiryu is paid 90,000 yen.