Maten Yuugi: Tawaman Quest

Babel Tower Tokyo is a super-high-rise apartment complex where a person's social standing is determined by the floor they live on—a twisted hierarchy deeply rooted in the building. This opulent, enviable luxury complex suddenly transforms into a hellish place where mysterious, monstrous creatures devour people. Can Takuya Kijima, a young man with neither education nor money, protect himself from the life-eating monsters and the money-hungry inhabitants? A tower apartment escape survival story!!

(Source: Comic Zenon, translated)