Story: The basic story is similar to Ranma 1/2, except the original manga came out several months before Ranma 1/2! Fear not, there's no copyright issue, switching body stories was just a popular trend at the time.
So how does this hold up? Pretty well in my opinion. The plot revolves around two detectives who are caught while on an undercover operation and killed. The first few episodes were pretty hilarious with Ranma and Rella trying to find out where the other as gone and eventually figuring out that their share the same body. From there they solve some mysteries and eventually the one they
were interrupted in at the beginning as well as figure out the circumstances of their current situation.
Art: TV Monkey Punch style. Always stylish. Too bad the anime is crappy. Even for 2003, the animation comes off extremely static. This didn't both me too much through as each frame by itself still looked good.
Sound: The opening theme is nice, but there's nothing really stand out here.
Character: Ranma and Rella are a great team. There are also some nice comic relief characters on the side and a touch of the quirky style I really love in Monkey Punch.
Enjoyment: Being a huge Monkey Punch fan, I enjoyed this quite a bit. If you're not a fan, you'll like it ok, but probably watch Ranma 1/2 if you're into the body switch thing.
Overall: Cinderella Boy is an enjoyable anime with a touch of style. The lack of animation is a bit annoying at times, but the story can speak for itself.