|Himiko-den has a rather hidden
back-story, in that a lot isn't explained right away (or at all, unfortunately, in the 12
episodes of the anime) - primarily because of the compressed time series the writers had
to work with. That fact, combined with the fact that very little has been said or written
about this series in English also makes it rather difficult to write about it or delve
into its depths. Generally, however, it is a mixture of fantasy and adventure, and
(according to the shitajiki) takes place in the third century. It details the power
struggle between Yamataikoku (the Yamatai kingdom) and Kunekoku (the Kune kingdom).
The first instance of the Himiko-den series was a video game for the Playstation console in Japan which, of course, never got translated and released anywhere else. I've seen the game referred to alternately as a strategy game and a dating simulation game, and don't know the details of it myself. It was a three disc game designed and released by Hakuhodo and Japan Fantasy Project, bore the catalog numbers of SLPS-01890 through SLPS-01892, and was originally released on March 11, 1999.
Next in line came the anime series, which is how I was exposed to the series. The series began airing on January 6, 1999 (which technically is before the video game release, but the game started development first as I understand it). The 12th and final episode aired on March 31, 1999. My best guess has it being a prequel to the video game of sorts, given the state of things at the end of the series compared with the opening of the game.
Some time later, and this is where everything gets foggy for me, there was also a manga published which was based on the series. Even less is known about the manga, so I can't even say how it fits into everything else Himiko-den. I do know, from the few scans I've seen, that it's a lot closer to the game (as opposed to the anime) in terms of character designs, and is even more fan-servicy (if you can believe that).