Hotel Inhumans

The most exquisite hotels in the world have certain standards: the finest food, the most sublime comfort, captivating entertainment, the latest weapons, reliable identity fabrication, and untraceable corpse disposal.

The name of this place where the people who have "forgotten their humanity" visit is "Hotel In Humans." The hitmen guests are welcomed by the concierges who never say "no."

(Source: Shogakukan, translated)