Such storylines already watched many times .
Here she went back to the past by a bracelet . She went into the body of lord who killed by assassination. There she fell in love with the assassinate and when everything was going to be alright , the lord soul was trying to come back into his body which the girl soul possessed . When the lord came back into his body he killed the assassinate and when the assassinate was going to die the girl came back to the body , he died and she went back to her world.
So basically what I had conclude by watching such gener that the on who go back to the past has a task to complete . When the task has completed then they come back to their world. Here in this drama she didn't do such thing she just need the bracelet. So I think it was a sensless story only because of the actors I had watched it. They did a great job.