This is a kids' movie that doesn't insult you by being a kids' movie. The mystery actually has a solution that makes sense, the comedy lands on adults the same way it lands on children, and the absurdity of a detective whose butt solves crimes is played completely straight. You spend ninety minutes watching a character literally called Butt Detective take his job seriously, and somehow that commitment to the bit is what makes it work. The pacing never wastes time on filler once it gets moving. This is the show for people who think animation comedy peaked somewhere around 2010 and are tired of waiting for someone to just make something that funny again without apology.
Oshiri Tantei: Sufuure-tou no Himitsu is a 2021 comedy and fantasy and mystery movie from Toei Animation.