The original writer had big plans for Princess, but he got fired upon being found out. See What Could Have Been below for details, but basically, it could be considered one of the few necessary cases of this.
Keep Circulating the Tapes: This series has not seen a reprint in any form since its cancellation, and no one seems interested in gaining the reprint rights.
No Export for You: Not surprising, considering how much nudity and violence there is compared to other versions of the franchise.
Princess was originally intended to kill off all the rest of the cast. Yes, even the actual Mega Man characters. Unsurprisingly, once the writer was found out, he got fired, and Princess herself ended up being Put on a Bus.
The series would have went on, and perhaps even concluded its story, had the publisher not gone out of business. Ironically, the North American Dreamwave comic ended up suffering a similar fate, except that one had even less issues published.
A spinoff that took place after Mega Man X4 would have been made, but the publisher going out of business (as well as the end of the main series) prevented this from happening.
The publishers had the option to translate a Manga adaptation of Mega Man 7. They chose to make an original story instead, and the results...