Undead King (2014)

Blurb
In a post-apocalyptic world, a group called the Nemesis infected the country with a contagion that transformed the population into flesh-eating zombies. A mysterious man known as the Undead King tries to fight back with a group of survivors and supernatural creatures called gangshi. A young high school boy finds himself drawn into this fight and struggles to stay alive while also trying to protect a young girl ganshi named Yoo Yoo that was left in his care.


Source: www.anisearch.com/manga/24308