I think it's a one shot and that Naraku has been defeated. Kagome is with Sesshomaru(platonic at that moment). She gives him information about the future. One day she tells him that she wants children and she is allowed to adopt them. The second world war is approaching and Sesshomaru has to break the news to the 'family' about moving away to switzerland. Here is when he realizes that he loves Kagome.
At the end she kisses him and says that she's been waiting for 200 years to do that.

If anyone finds this story please do let me know it's name.
Thanks a bunch.