Note: The fic may have been posted on other Fanfic sites like ff.net. I don't remember the name or author of this story and read it around 2008. From what I remember of this fic it wasn't completed and had around over 10-15 chapters. This is from what I remember.
If anyone remembers any stories with past and present day Sesshomaru with this similar story plot let me know. The fic I'm looking for was very extensive and well written.
Takes place In Kagome and her friends attempt to restore the shikon jewel and defeat Naraku. It's quite a twist you see It Involves a past and present day Sesshomaru. In the feudal era Kagome and Sesshomaru end up having random meetings with each other, however there not to friendly even though Kagome tries to be nice in order to change his mind (basically his views that are prejudice towards humans of them being only good for sport and that demons are the stronger species who are supreme)and befriend Sesshomauru he however rebuffs her attempts and arguments and insults ensue between them. Kagome and her friends are looking for a break and stay in Kaede's village. (Kagome's friends suspect she's a target though her friends don't let Kagome know)Naraku however has a plan inorder to get the jewel hell have to corrupt and destroy Kagome for her purity and innocence get in the way of him having complete control of the Jewel.
Kagome ends up going home through the well for about a few week's to catch up with school and be with her friends n' family. What's interesting is that Ayumi knows about Kagome's quest in the feudal era and she's the only one out of Kagome's friends who know's about her actual adventure's in the past since she first fell down the well. Kagome confides in Ayumi and tells her about what she thinks of Sesshomaru; as someone who has experienced so much hardship that he can't help but distrust everyone he even intrigues her. She ends up going to school the next day and shockingly there's a new teacher (history teacher?) who Kagome recognises as Sesshomaru under a guise no less. Sesshomaru ends up speaking to Kagome at the end of class and says he cannot reveal the reason as to his presence only that he wishes to prevent something from happening in the past, however Kagome is wary and suspicious of Sesshomaru. Note: also Sesshomaru is constantly looking at the date and time of his watch, he tries to take Kagome out on outings to get to know her or so she think's, but, infact he's trying to keep a constant eye on her to prevent her from leaving to the past early; there is immense sadness when he looks at Kagome and immeasurable guilt he feels towards her for what he did in the past.
Ayumi noticing Kagome's unease around their new teacher questions Kagome and she let's Ayumi know he is infact Sesshomaru. Kagome is soon to return to the feudal Era and Sesshomaru is aware the time similarity so he intends to get close to Kagome in order to prevent her from traveling back in time in order to fix a mistake he made in apparently that caused him to hurt Kagome irrevocably. Before kagome leaves to head to the Feudal era, Sesshomaru and Kagome spend the weekend together at the end Decides to warn Kagome by scaring her to not return to the past saying he'll tell her the truth if she'll only stay in the present and not go to the past for three more day's for if she leaves she'll never come back, Kagome asks Sesshomaru why and what'll happen, he refuses to answer her. Kagome doesn't feel inclined to abandon her friends by not coming back on time Ayumi and Kagome talk that night and Kagome leave's in the morning. Back to the Past: Naraku has been waiting for her, her friends are distracted and unable to defend herself she runs further into the forest, she run's into Sesshomaru begging for help, Sesshomaru scoff's though seeing an opportunity to conquer the miko he refuses to help her till she admits she is wrong about her beliefs in demons and human's being alike and both being neither stronger or weaker than the other. Kagome refuses to take back her words for it would make her a liar and which would only prove to him to distrust humans and anyone else. Sesshomaru in his anger grabs her demanding she submit and that he is right. She still tells him he's wrong and he throws her to the ground telling Kagome she bring's her fate down on herself and she deserves it for she being a weak fool. Naraku shows himself having witnessed the whole exchange appearing feet away from them Sesshomaru and Naraku acknowledge each other and Sesshomaru begins to leave well Kagome continues to beg Sesshomaru to come back and help her, he keep's on walking hoping that Kagome will learn her lesson in having such a faithless belief of being trusting. In the Future Sesshomaru is outside the entrance of the school looking at his watch worried for Kagome hasn't showed up for class for the day (or a few days) Ayumi see's Sesshomaru and asks if he's alright. Sesshomaru questions the reason for Kagome's absence for he was told she wasn't feeling well from her mother; Ayumi knowing the truth about who Sesshomaru is tells him the truth and that Kagome went back to the past yesterday. In disbelief sudden dread come's over him and tell Ayumi that he failed and that Kagome will never come back through the well. (I believe he tell her the whole story as to what he did and that he also had continuous involvement in hurting Kagome even after Naraku took her)
Hopefully this Story is around still I never did get to continue reading it.