Yu-Gi-Oh Monster Summoning system in a Fantasy world!

What do you get when a homeless ten-year-old gets the ability to summon monsters of untold power? Overprotective monsters? Check. People mistaking him as the son of a powerful Mafia family? Check. Lots of wholesome and fluff moments? Check. Chaos? Oh, you betcha. So follow the journey of Demi as he brings himself up in the world, all the while creating a family of monsters. Oh, did I mention he's a cute catboy? Cover art's not mine.