Yes!!! That's the one I was looking for. I have been trying to thank you ever since you posted but the website has been so slow and it doesn't post. Hopefully this time, it goes through.

Thank you so so so much again! I am rereading it and I am halfway through haha

Hi there!
First of all THANK YOU so much for helping me find the last one I was looking for but yet another one came to mind and I only remember specific details about it.

Okay, is set in the past. Kagome somehow ends up living with Sesh in his castle and takes part in his counsel against the enemy. I remember Kagome being attracted to him and I remember him being attracted to her too. I remember somebody from Sesh court inviting a demoness and when she us taken to Sesh study for an introduction, I remember Sesh noticed how curvaceous she was when she bowed and hoped that she wouldn’t find trouble with the other male demons where he was sending her to stay. This demoness I believe uses magic in order to physically attract Sesh. She is invited to Sesh council too and Kagome notices how his eyes are very drawn to her and they kinda glazed cause he is basically daydreaming having her or something like that. One night, Sesh follows this demoness outside and I believe they making out and Kagome stops them and he gets aggressive with kagome for interrupting them but kagome was very hurt by this and returns to the castle.
At the end, I think there is an all out war and everyone is worried about this demoness trying her tricks on Sesh to render him unable to fight as he is very sexually drawn to her

I hope someone knows it. English is my second language and I apologize if things don’t make sense. Thank you so much in advance.

I think you are looking for Sunset Love by Aurora Nyte.

www.dokuga.com/fanfiction/story/124/1?author=123

The demoness is brought into the castle as the "lost sister" to a male already there. She is a shape-shifter.