Koma is a demon of the Shicarion Family, which moved to the human world long ago. His people are called purifying gods and have statues dedicated to them at shrines. Koma is very perverted and will ask girls their three sizes, he even asked Aoi for her panties in exchange for his assistance. Even when he is in battle he will say lecherous remarks about any girl in the vicinity. He is constantly teasing Aoi which usually earns him a harsh beating from her. He believes if he were to be killed by a cute girl, that would be the ideal way to go.
(Source: Beelzebub.wikia)