This manga is close to the same story as Outlaw Star.
The Story was a bit too playful for my taste. No real impending death is to be found here. Pretty much a love story of pirates. It does have an overall story line but it really doesn't go into depth at all.
The Characters were developed but could have been better. I feel this is because the lack of story. However, the main focus is on the Love Triangle that involves the 3 main characters, though it is explored pretty weakly and a bit confusing at times.
Overall it's a good anime if you want to watch something good, but if you want to watch something Awesome there are definitely better choices. It's was still worth watching it all the way to the end so that says something.