The head of Momozano family and director of school. He's a old pervert and grandfather of Mei.

Teacher Sorata Muon carries on his family's centuries-old old tradition of being the master thief Mouse who can steal anything after properly alerting authorities of his intentions so they can be there yet fail to stop him. He is assistedby 3 nubile female assistants who also use the teaching cover and who, in typical Satoru Akahori, favor tight/skimpy/bondage outfits over their ample curves as they constantly pursue Sorata much more than he pursues them, although the girls do get some attention from their master. Not only is Mouse pursued by the girls &amp; the local law enforcement authorities, there is also a secret art protection society employing the services of a former ally of Sorata's after his pretty little hide, all in 15 minute episodes.
 
(Source: Anime News Network)

Father of [Bryce Papenbrook](https://anilist.co/staff/95732/Bryce-Papenbrook)

For 400 years, there was a family of thieves stealing money and priceless property, particularly those items that were originally illegally stolen. The main motivation is that anything and everything can be stolen, no matter how much they protect that item. And in those years, that thief was only known by one name, Mouse. 
In the latest version, a young college art teacher named Muon Sorata is the latest to take up the name of Mouse. He is surrounded by three highly devoted and attractive assistants who help him pull off heists of art museums and landmark towers. The thieves had the power and resources to steal entire buildings and take structures out to sea but never get caught. Mouse is also known for not abandoning those who serve him, even if it means his capture.(Wikipedia)

Fuyuharu Momozono