I think this needs Fantasy label along with Historical. Is a very fantastical take on Shaman Queen Himiko/Pimiko. Her story, location and even existence and real identity are so uncertain and debated that to make a story about her you have wind up like 70% of it, on top of the magical elements this makes this manga mostly a fantasy.
Shame about the abrupt end because I was curious about what happens after Shiki becomes human again but guess is the result of running out of material to adapt. The next record available is about her burial.