William is an insufferable prodigy who accidentally summons a demon and somehow that makes him worse, not better. The real comedy isn't the supernatural chaos, it's watching a kid so convinced of his own logic that he tries to rationalize demons out of existence. Every episode is William's absolute confidence colliding with the one thing his intellect cannot calculate.
William Twining is a brilliant aristocrat facing his family's financial ruin. When his uncle's business collapses, William takes matters into his own hands, ransacking the family estate for anything valuable enough to salvage their reputation. His search leads him to a sealed chamber hidden beneath the mansion, where an ancient magical diagram covers the floor. Disturbing the seal accidentally summons Dantalion, a devil who drops a shocking revelation: William isn't just some random aristocrat. He's a Designator, one born with the power to elect the next ruler of the demon world. Now demons come knocking, each one desperate to curry favor with the one person who holds their political fate in his hands. Between managing his family's crisis and navigating the schemes of otherworldly creatures, William must figure out exactly what he's gotten himself into. Comedy clashes with genuine supernatural stakes as William deals with demons who range from genuinely dangerous to absurdly needy. It's aristocratic intrigue meets demon politics, wrapped in mystery about what his bloodline really means.