Ataru is a very peculiar detective who helps the police now and then. This case is not so much a puzzle, but more of a cat and mouse thriller. Though the tone is often light, with comedy mixed in by some side characters.
The case follows after the TV series Ataru (2012) of 12 episodes. Unfortunately, the movie has a rough start where many characters and relationships are not introduced properly, supposing that you know them from before. There is nothing wrong with watching the movie first anyway, just that you will get a weird and confusing first 6 minutes. When I first saw it in a movie theater in Japan, I immediately thought about walking out, but fortunately stayed, because I had nothing better to do.
The story eventually stabilizes to stand on its own. Still, there are flashbacks to the series. All this is a small minus, but not fatal.
Ataru is an original detective that carries the movie, and even gets involved in some touching scenes. On the other side stands a capable and stylish antagonist with a backstory and complex motivations, who is able to cause a lot of trouble.
The larger than usual cast makes it lively, but the comedy is sometimes irritating. It's an entertaining movie with lots of contents and some cool moments.