Good start

I very much like this Fanfic. Its pretty intresting and i like the concept of Kagome being from the fuedal era! :) I can't wait for more chapters!!!

The story is moving much too quickly, and I didn't see any crazy Kagome reactions to her mother lying to her about a lot of things. Never mind whether her body was changed, she should at least retain some of her personality and have some issues with that. 

My suggestion is to break up the first chapter into at least four chapters:

The first one could deal with Kags finding Inu with Kikyo - and maybe end it with her going through the well and seeing her mother as a youkai. I caution you to be extremely careful with your scenes here because unfortunately finding Inu cheating is one of the top 5 ways people on Dokuga start fanfictions.

The second can deal with explanations from Mom and Kags reacting to all of that, and some details of her brother finding out what was going on and them all discussing the past at length before making the decision to return home to the past. Also it would be nice to hear where Grandpa and the shrine fit into this - how on earth did youkai change themselves into humans and manage to trick a wise old priest, and manage to convince him to let them live at the shrine as part of the family? How did they time travel?? AND HOW IS KAGOME A MIKO?? These items need to be addressed in order to keep your audience from being confused.

The third can deal with going back to the Inu-tachi and explaining everything. Btw, about the time slip - if you're going to have her have disappeared for more time than she thought she was gone, a good way to show the passage of that without confusion would be to show a snippet of the others wondering where she is and being worried about her disappearance and angry at Inuyasha for him being with Kikyo. Why now, all of a sudden, is the well spitting her out after a longer period of time when time always moved the same on both sides of the well before?

The fourth COULD deal with Sesshomaru, but the way you left things with Inu and Kikyo was a bit open-ended and unless you had a specific reason for that, Kagome should get to yell at him for the way he behaved. And why is he suddenly attacking her for no reason, when she's obviously not harming his friends?? Even Inu has better tact than that and if she was hurting the others it would be merited for him to attack but since they're just talking, it doesn't feel real to me.

Deal with Sessh after all of this, and maybe even after another chapter or two, showing her getting her memories back slowly and getting used to her abilities again.

Dealing with the pacing issues and breaking up the story the way I've suggested will make the story flow better and feel more true to what we know of our own lives. If I came home and found out I was really a demon I'd go crazy on my mom for having lied to me for so long. Being kept in the dark about all of that AND still going back in time to put together pieces of a jewel while almost being killed by my lover because we didn't recognize each other?? That would be traumatic.

I like the idea of the story and I didn't see any huge grammar or spelling issues, so you did well there. Just work on your pacing, please. I'd really like to see more of this but at a much less confusing rate.

That was interesting, in a good way. I don't know what anything meant though.

wow!!! what an amazing first chapter! i'm extremely excited for the next one. i just love when kagome is a youkai!!! please update again soon, i can't wait!!!!!!

can't wait to see where you go with this story. good job!

next chapter please

Beautiful first chapter, I look forward to more.