Gunmania manga

Gunmania summary:

Bando Eiji is a hitman (Though he hates to be called as such...) with more than a few screws loose. This 3 chapter mini-series from the creator of Hellsing follows the escapades of the demented Bando as he picks off one target after another whilst simultaneously confusing the hell out of onlookers with his unhinged mental disposition! (summary from MAL)