{{Note: this review is based on the first 39 episodes. After the series is done being fansubbed and I have watched the rest, I will update this review.}}
Tantei Gakuen Q is, overall, very fun to watch. It's fairly formulaic (they always describe all of the hints one by one and how all of the "tricks" work), and sometimes it's a bit cheesy because of this, but the plots are generally rather clever and I found just about all of them to be interesting. It's not even entirely predictable, which is a plus.
Story: The story here is mostly episodic. The main characters are enrolled in a detective school for a famous and talented detective, but they're basically full-fledged detectives that get the full cooperation of the police. Sometimes a case will last for several episodes, or sometimes for only one episode. The cases are almost always murder cases. Later, a bit of an ongoing story forms which ties into several of the cases. I found that the cases that lasted more episodes were a lot more interesting. My personal favorite cases were the "Jack the Ripper" case, double village case, the seance case, the snuff film case, and the violin case. In fact, I don't remember a single case that didn't entertain me thoroughly. They can keep you guessing the whole way through sometimes. Sometimes some things are predictable, but I found it to actually be tons of fun to be constantly thinking of the possibilities and figuring out the clues or hints and deducting what could be deducted. For the times that I was able to predict the outcome, it was actually rewarding—usually when I can figure out a plot's outcome, that's a bad thing, but it works well in this series since it's a clever mystery series.
Character: I really like the main characters in this, as well as some of the side characters. There's not that much development, overall, but the characters still work very well in this series.
Kyu, the main character, is fantastic at finding clues and figuring out what's going on. He's very spirited, kind, and brave, and makes a good main character.
Ryuis also great at figuring things out and is very intelligent. He's not as good as Kyu at figuring everything out, but he's very close, and he sometimes even figures things out before Kyu does. Ryu is definitely the most interesting character, however, with the most development—he's a very mysterious individual, but as time passes you get to learn more about him. The two, Kyu and Ryu, are able to figure out just about any case, with the support of the other three main characters.
Meguhas "photographic memory," and it seems to be flawless. Much of the support she gives in solving a case is directly related to remembering in perfect detail what she has seen, though she's able to analyze things well enough, too.
Kintais a fighting specialist, as well as an errand runner. If someone needs to call an ambulance, he'll do it. If someone needs to run somewhere fast, he'll do it. If someone needs to get taken down, he'll take them down. He's not too intelligent and usually doesn't figure things out so fast, but he sometimes helps the others solve cases in his own unique way—he "feels" rather than "thinks," most often.
Kazuma is the youngest in the group, an elementary school student that happens to be great with computers, excelling in programming and designing simulations on his laptop. He's actually able to figure out some things that even Kyu and Ryu can't seem to get, and this usually involves using his laptop for playing out situations, analyzing data, or researching information on the Internet.
As for the
... the teachers are all cool, though they usually aren't very active. I would have liked to have seen more of all of the teachers, including Dan Morihiko, the famous detective that runs the school. The episodic characters, notably the criminals, are generally interesting, and their reasons for committing their crimes are almost always perfectly believable and sometimes tragic.
Enjoyment: Extremely enjoyable. I haven't watched through this many episodes this fast in over a year. I saw all 39 available episodes in the span of 3 days, and I enjoyed almost every minute of it. Each time there was a case that lasted into the next episode, I wanted to get right into it, and even after a case finished I wanted to find out what the next case was about. This series is just so easy to breeze through because of the tricky murder scenarios and the cool characters. If the last 6 episodes were available, I'd be watching those right now instead of writing this.
Value: I wouldn't personally purchase this series, despite liking it an incredible amount. If I were to rewatch it, I do not suppose that I would enjoy it nearly so much, because I would already know what happens and who the murderer is. Thus, rewatch value does not seem very high. Still, this series is definitely worth watching through. I wasn't sure how much I'd like a detective anime about a bunch of kids enrolled in a detective school. They're pretty much full-fledged detectives, though, as I mentioned previously, and their cases almost always deal with murder, so while it's sometimes childish, it's usually quite serious. I'm definitely glad that I have seen up to episode 39, and I eagerly anticipate being able to see the last 6 episodes when I am able to. Value summary: watch it once and then recommend it to your friends.
Animation: The animation is colorful, for the most part, but the actual quality is not entirely consistent and is often rather plain. Sometimes the legs and body parts look really awkward or misshapen. You can always tell who is who (as long as they're not disguised), at least. The character designs aren't too interesting, but that's fine with me because they're often undercover so they don't really want to be all flashy. The animation quality doesn't detract from the enjoyability of the show, however, since it is at least "acceptable."
Sound: The voice acting is good—I had no complaints, though nobody particularly stood out. None of the main characters have annoying voices, though one character in particular that's in a few of the episodes has a disturbingly annoying voice (you'll either know it when you come across it or you won't mind it). The background music is can get pretty repetitive, but I actually liked a lot of the songs since they fit the mood most of the time. As for the OP and ED songs... I didn't listen to most of them. I usually wanted to get right into the next episode as soon as possible.
Overall: Tons of fun to watch. I highly recommend this to just about anyone, even if you don't think you'll like a detective anime series. I was very unsure, myself, but I'm very glad that I decided to watch this. If you don't like it by episode 7, it's probably not something you'll like, but I suggest at least watching the first 5 episodes to decide if you want to see more. :}D