Re:Zero kara Hajimeru Isekai Seikatsu [Abbreviated Re: Zreo] is in the same category of anime such as Steins Gate, Erased, Madoka Magica, and The Girl Who Leaped Through Time. (As far as I can tell T.G.W.L.T.T. inspired all the others. It’s also the best out of all of them I may add.)
All of these anime have a similar theme. Basically all/most characters die repeatedly. Thanks to some kind of spell or curse the main character can or will time travel in an attempt to prevent side characters from dying. The main character fails to save the side characters multiple times throughout multiple episodes. Honestly you can say that “death” is the main character (enemy?) in this genre of anime.
This AMV focuses on the main character Natsuki Subaru and a side character, Rem. Can Subaru save Rem from an inevitable death? How many times will she die? You’ll have to watch Re: Zero to find out.