Bullet the Wizard

In a supernatural 1960s era America, there lives a cursed magician known as "Bullet the Wizard." The supernatural side of his life includes a magic gun and his childlike accomplice called Titi-Alice, who can keep his life-threatening curse at bay. One day, the two of them sneak into a casino owned by the dangerous Leland Gang in order to steal their magic gun. Complications in their plan lead to the involvement of the reluctant Paula Winston, a journalist working undercover as a waitress. Now Bullet must find a way to achieve his mysterious goal while also keeping Paula safe from the deadly Leland gang!

(Source: MangaHelpers)