The Silent Fox And The Spider! (Naraku x oc)

Her parents died by the hands of Shippo's parents because they wanted to rule the lands of the south, however, they never realized that an infant was in the rubble. They then left for the rest of Umiko's parent's lands to declare them officially dead. When they did, Sesshomaru's mother, Inukimi, found her whimpering under a burning wall that was supported by large piles of rubble. At this point, Umiko not only didn't have a name but was also only an infant. Inukimi raised her with Sesshomaru for about 10 human years, before getting banished by Sesshomaru from the western lands. It was then that she asked him to take care of her and protect her as though she was part of his pack.

Naraku x Oc