Hi I believe you're looking for Belovedstrangers
Bound by Corruption rated MA, and it is complete.
Summary,
Inside every individual, darkness dwelled large or small. A young woman, cast under her elder sister’s shadow, was bent on proving her worth. A terrible threat hung over her village, giving Kagome the opportunity she had been waiting for. On a mission to save them all from the hearts of evil men, she journeyed to the Inu no Kami’s temple to beseech divine intervention. Instead, danger befell the headstrong woman. Rather than obtaining help from a merciful god, another stepped in to slaughter her enemies, but for a price. An Inugami did nothing for free.
They are also working on a sequel that is MA also but it is not complete.
Oh almost forgot, the original oneshot is in her oneshot collection
A Smell So Sweet in chapter 2, again MA so no YIMS!