This is just another conan movie, and does nothing to move the story forward.
But it was more fun than most because Kaito Kid was in it. And to juice it up even more, Sonoko's karate boy friend too was there. He had a major part in this movie, and together they do increase the fun factor.
The mystery part of the story, was typical conan fare, if you have seen enough conan, its pretty boring. But the interesting and fun characters that we have been seeing for more than 20yrs, make up for it.
If you are following conan, you will definitely be seeing this. If not, give it a , go see a far better rated anime.