EDIT: I was going to give Genbu Kaiden four stars, but then I got to volume 6 and Takiko made me want to stand up and cheer, so five stars it is. She makes up for Miaka so much. Go Takiko!
I moved directly from Fushigi Yugi to this series, with only a very short break in between, and as a result skipped about a decade of Watase's career...
...and I'm so very, very glad.
From one series to the next, everything has improved. True, I'm only four volumes in, but I can already tell you I like Genbu Kaiden a lot more than I liked Fushigi Yugi at the same point. The art is more interesting, the enormous shojo eyes less exaggerated, the character designs compelling. Takiko, priestess of Genbu, actually and legitimately kicks ass. She's brave, and she knows how to use a weapon, and she does use it. She's also got that deep inner strength that Watase argued was Miaka's sort, but in Takiko it's much more compelling. Her love interest is fascinating, and frankly not the least what I would have expected from this series. Every character has inner conflicts, and there are parallels between the troubles of the Genbu Celestial Warriors and Takiko's own father problems.
The formula is basically the same: Girl sucked into book, becomes priestess, meets her first few warriors, searches for others with the help of various supernatural characters, gets sucked back into real world when things get truly tense. It could have been trite and boring, but the amount Watase has improved in her storytelling, characterization, and art make it refreshing and new.
While probably best for someone who's already familiar with Fushigi Yugi, this series could stand on its own and is definitely better than the original. (So far, that is.)