This is the kind of manga you'll like if you want romantic angst and repetitive plot development. In other words, it's like any other shoujo romance manga with "forbidden love", except with ninjas and time travel and convenient plot devices and a relapse of all the romantic progress and character growth that is ever made. And isn't it so convenient that
the real princess lost her memory and gave up being a princess, therefore making it easy for Kagetora to abandon her?
Isn't it convenient that Beni's potential "supernatural powers" suddenly appear a few volumes in, without a hint of them beforehand?
Everyone in this manga is full of angst: the villains, the heroes, basically anyone of importance. And the heroine is weak. She seems strong, but everything she does causes more trouble and Kagetora still ends up coming to save her. He has to extricate her from the mess she made trying to "save" him. She's always crying or about to cry about something. Fortunately, she's not colossally stupid, but I can't like her either. And Kagetora always feels guilty about something. I guess he's cute for a manga guy, but he's completely intolerable the way he wavers back and forth about how to treat Beni.
In other words, this series could've been nicely wrapped up in about 3-4 volumes. There's only four important plot points: the past princess, the fiance, the antagonist, the nasty father. Instead of a nice, tight, well-planned storyline, there's angst on top of angst. If you like that, then you'll LOVE this. If you like a good plot and developing/developed characters, you are going to be driven crazy by this.