I've seen conflicting opinions and I get why. To my opinion, it's all about the mindset of the viewer starting this series. Before watching I think you need to be ready to watch a somehow goofy drama. The title and poster first led me to think it was a serious drama, but it's really not. And if you're not in the mindset to accept ridiculous acting and goofy scenes in a serious setting, then you're probably not gonna enjoy it. I don't think it's the drama that is "bad" but rather the viewer needs to be ready to go along with the peculiar mood created by the leads, and if not, it's probably come off as bad or ridiculous. But it's actually made on purpose, and I though it was interesting to have, for once, a detective story that isn't 95% serious. dark and guns. I do enjoy those, but I thought a dorky detective story was refreshing. The "cheap" ambiance was actually made on purpose and found it interesting. The main story is quite good, funny and stimulating. The cast is also very good, and it was nice to see the actors giving a funny side to their own character for that mystery drama instead of sticking to a serious one like a lot does. The main problem was that some stories were somehow easy to figure out, even before the main character's search process. Yes, some episodes are somehow easy to figure out but others are harder to guess and that makes it up for it, Not to mention I really liked how the drama really explorer the mind and feelings of the characters. I also heard criticism about how MONSTERS is somehow repetitive. The drama do follow the same pattern from one episode to an other, but it's a detective drama and a lot of dramas of this genre follow the same pattern. (or even other genres, it''s common to have a pattern and follow it) The characters were fascinating, and endearing... I especially like Yamashita Tomohisa to be this cute and funny, it was really refreshing to see him in that kind of character after so long ! It somehow reminded me of his cute younger self from Nobuta no Produce~ It's a refreshing drama I'd recommend you to watch !