 If you liked
Zetman
|
 ...then you might like
Ratman
|
Both mangas are well in a way superhero themed mangas. While Zetman is more dark and mature, Ratman has a more lighthearted and has somewhat of a comedic approach to it.
Zetman and Ratman takes the concept of heroes and transform it into a story with complex developments. The main characters plays on the role of a hero although meets unexpected consequences throughout the story. Their adversaries are dangerous and the MC usually puts their own life at risk. Expect decent action with mild comedy. There is more violence in Zetman and fan service. If you're into stories involving heroes fighting against evil, give both a try.