I want to highly recommend the above manga: Apocalypse no Toride.
Synopsis: The four boys at the top are our protagonist. They’re roommates in a juvenile detention center and they get along. Enter the zombie apocalypse right from the start. Now you’ve got a group of “at odds” juvenile delinquents, normal zombies, cultist, whatever the fuck those dog like things are, Bokor (the guy and the chick using the dead as a throne because that type of “zombie” is just that bad-ass), and seals… but not really seals. The oceaun will never be safe again.
So, if you’re if you’re up for a horror/shounen/action/mystery type of deal that has some comedy and some edge-of-the-seat-nail-biting splendor. Check this one out. I’ve been following it since it only had two chapters and I regret nothing.
Warning: Language, Blood, Gore, Violence, and Zombies.
Have fun! (The Link is the manga title!)