Need Recommendation on Time Travel or Regression JDramas.

Kindly recommend me your fav time travel or regression jdramas. I have watched many dramas and movies of these genres of other countries and now i am trying to find some from Japan. I love these genres when some personal drama is major part of them, like some past regret, an unfinished bond, etc. Like protagonist using that chance to grow as a person or to trying to get closure on the unfinished bond, making amends, etc.

Do recommend me your fav or best dramas on this genres.