This series was a big guilty-pleasure read for me. I liked it and read the half of the first book plus two and three in one sitting. However, it was not the most enlightening thing one finds in manga. 
 First of all, it was ridiculous and random. You don't need me to tell you that, just look at the synopsis. I'm not terribly sure that the names are accurate either, but at least there are no actual Hittites to be potentially offended by the portrayal of their culture. 
 Secondly, it was kind of sexist. Yuri was always reliant on her boyfriend or prince Kail or Tito to save her posterior. Luckily, she gets better in the next few books. 
 In other words, think Tiger's Curse except without were-tigers and magic and dumb cultural stereotypes. Read this instead to save time and brain cells.