Fushigi Yuugi: Genbu Kaiden (Fushigi Yugi: Genbu Kaiden) - Watase, Yuu

Takiko Okuda is a strong-willed girl living in the Taisho Era. She needs to be strong -- Oosugi, the one man she's ever loved, is a married man; her mother is terminally ill; and her father, Einosuke, has not been home in over a year. When at last Einosuke returns, it's with a notebook full of Chinese scribblings that seem more important to him than the death of his wife. Furious, Takiko steals away his completed translation -- "The Universe of the Four Gods" -- with the intention of tearing it to shreds, but the instant she opens it, she's surrounded by light... And it is said that this is how the legend of the Priestess of Genbu began.

(Source: ShoujoMagic)
Included one-shot:
Volume 6: Ayashi no Ceres Gaiden

Fushigi Yuugi: Genbu Kaiden was published in English by VIZ Media under the Shojo Beat imprint from July 5, 2005 to March 4, 2014.