An extra, self-contained episode focusing on Kasumi and tanpopo. It's nothing amazing, but it's enjoyable. It has all the quality of the main series, except it had a bit more humour and action(which makes sense considering it's a standalone episode) I disagree with the reviewer who said it's better than the main series. I'd say this episode was nice, but a bit lower quality than the main series ones. On that note, I was sort of disappointed it didn't tie into the story at all or add much characterisation.
Anyways, if you liked WCW, I'd recommend watching this.