This whodunit series has interesting cases, most of which are solved within the same episode. It manages to have quite a few surprising endings without trying too hard to have twists or maintain suspense. I like the classic feel to this series. Unlike some other series from the same genre in recent years, it doesn't have a lot of focus on forensics and high-tech equipment but focuses on locked rooms. The detective is also not a detective but a locksmith who is more interested in unlocking rooms. It is charming in how it doesn't take itself too seriously, sometimes making fun of the genre itself.

What makes the series stand out is perhaps the overall quality of the production. The stories are good, the main characters are entertaining and likable, and it is well-paced. I actually watched a couple of episodes of the Chinese remake of this series and I dropped it to watch this. The stories may be similar (based on what I have watched), but this is just so much better.