Although I only got into it recently, I love Detective Conan. I love the exciting deductions and quirky mishaps that occur along the road of a great mystery show...and best of all, despite the murder, guns and violence...it remains child friendly!
If you haven't heard of the series before, its about Kudou Shinichi, a high school detective who witnessed a shady deal by somesecret organization. One of the members snuck behind him and drugged him with an experimental pill. It caused him to shrink back to the size of a child. He told Professor Agasa, a genius inventor, about the events and he told Kudou to keep his identity a secret to prevent the organization tarrgeting his loved ones, especially Ran, his 'girlfriend'. Professor Agasa designs gadgets for Kudou to use and Kudou finds himself living with Ran under the name Edogawa Conan. Ran's father is a private detective and so Conan helps with the cases...secretly. He helps so much that Rans father's reputation increases from drunken detective to famous.
Back to the movie, the movie is about murders occuring in twin tower buildings in Japan. Mouri(Ran's father) was invited there for its opening ceremony by its owner, an old college friend of his. Things get weird when one of the people on the council dies and even weirder when the programmer for the company is found shot.
Yet another murder occurs and soon after this Mouri thinks he's got a foolproof deduction which is destroyed by Conan's superior intellect and experience. The mystery is uncovered and the criminal is prosecuted. Simple.
It all sounds pretty straight-forward but the plot twists along the way make you make your own biases towards who the killer could be and the antics of the 3 children who accompany Conan draw your attention too. Ai's secret late-night phonecalls also raise suspicion in the team and you find yourself linking back to where the story all began. It's engrossing stuff!
I will say it's better to watch a few episodes of the series firrst to familiarise yourself with the characters but that also goes without saying really. You should also check out the previous movies too as they are just as good, if not better, my favourite being the 4th movie.