No Guns Life, Vol. 1, 1

After the war, cyborg soldiers known as the Extended were discharged. Juzo Inui is one of them, a man whose body was transformed, his head replaced with a giant gun With no memory of his previous life--or who replaced his head and why--Inui now scratches out a living in the dark streets of the city as a Resolver, taking on cases involving the Extended.

When a fellow Extended showed up in Inui's office--on the run from the Security Bureau with a kidnapped child in tow and asking for help--Inui almost throws the guy out. But Inui's loyalty to a brother Extended makes him take the job. Keeping the child safe won't be easy, since everyone wants him, from the mob to the megacorporation Ber hren, which sends out a special agent who knows exactly how to deal with the Extended...