Корсет

The mayor of Daten City and the boss of the demon sisters. His true form is a demon with pale blue skin, bony features and a conical hairstyle; when appearing in public he appears with more flesh and slicks his hair back, though his demonic features remain. He wears a rather tight corset and is constantly scratching his back. He also wears hooks to stretch his mouth and buckles on most of his body, and is seen often tightening them. He appears to be into self punishment and a fetish for bondage like Stocking. This evident from the buckles on his body, mouth stretchers and his namesake, the corset.

He has an extreme interest with Hell's Monkey, a mystical key possessed by Brief, which has the power to unleash the forces of Hell on Earth. He is also Garterbelts counterpart and seem to have known each other prior to the story. (Source: Wikipedia)