BEM: The Complete Series

Libra City is a sprawling metropolis, whose districts split the rich and the poor. Hiding among the populace are three humanoid monsters-Bem, Bela, and Belo-who protect humanity and hope to one day become humans themselves. However, when a Mysterious Lady threatens their way of life, Bem, Bela, and Belo are pulled into a plot unlike anything they've ever known.