My Restaurant's Guests are All Abnormal

“At first, I thought I was running a regular restaurant, until I realized my customers were not quite normal...” … Chen Ze just kindly helped up a fallen old man, but received a reward for inheriting a Dream Restaurant! On the first day, he met an Otherworldly Girl with a pink avatar and an elf like appearance. But she called him Inferior Race, and even waved her hand to summon spider silk to bind Chen Ze. It turns out that this restaurant belongs to Necromancer, and Chen Ze was also misunderstood as a subordinate of Necromancer. Then, more magical creatures followed one after another… Chen Ze finally realized that his guests... all don't seem to be human?! — Description from novelcodex.org