Warning: I have no idea. Violence, and possibly nudity, but nothing too graphic. Another Hana to Yume series.
Acquisition Method: The OVAs are licensed by Media Blasters, but have not been released yet. The manga has not been translated in any form.
Format: 19 volumes of manga, complete. 2 OVAs, complete.
Genre: Occult/supernatural/mythological shoujo.
Plot, Characters: Because I haven't had the opportunity to read this series, I am going to rely on others' summaries. Taken from The Ultimate Manga Guide:
"Shoujo supernatural/sorcery series about the adventures of Kuraki Fuzuchi and Takeo Nanachi. The title "Yakumo Tatsu" refers to the literary name of the Izumo region, the site of many Japanese myths and legends, where the whole story takes place. Kuraki is a high school kid who's an exorcist with great spiritual powers which are manifested through an ancient mysterious sword that he carries around. He is trying to collect other sacred swords with the help of Nanachi, his college buddy who's still unaware of his own latent powers. The two are reincarnations of a miko (a medium for the gods, usually female but in this case, ex-Kuraki was male) and a famous swordsmaker respectively from the ancient times. Kuraki's very good-looking (all the girls swoon over him...) and a martial arts extraordinaire but he's pretty cold and distant because he's got a dark secret while Nanachi is very annoyingly cheerful and generous."Mangallaria also has a short description and a few black and white scans. Here is some history on the myth from which the story is derived. If that's not enough to sell you on the series, feast your eyes on some artwork (full-color, scanned from the artbook) and the author's official site. There's also tons of pretty fanart to go with that, much of it of the shounen-ai variety (this is a very slashy series). Aestheticism even carries doujinshi for it. Art aside, Yakumo Tatsu is said to have a very complex story as well as highly developed characters.
Seiyuu: The only one I could find is Tomokazu Seki as Kuraki.
Technical details: No anime or translation available, so I can't comment on this. Really pretty art that looks kind of old-school.
Music: Can't comment on this.
Squee factor: Come on, folks! It has pretty boys! Swords! Mythology and supernatural elements! Homoerotic UST! What more can you want?
I have never read this series, so everything I know about it has been gleaned from reading others' summaries and flipping through the pages of the manga volumes I own. There's no way to read it except in raw Japanese. The mangaka is extremely popular in Japan, but virtually unknown here. I would love to see Yakumo Tatsu picked up by any translating group. If anyone knows how I could go about doing so, or has the proper connections, I would be forever in your debt. If there is someone willing to translate/scanslate it, I will gladly scan in the entire thing.