Interest Stacks

Stories with characters that jump back in time for a Second Chance and do things better in a Modern World Setting. This is for stories that go back in time while remaining in the same world, not another world. Also Regression/Regressor, Time Travel, Time Rewind, Revenge, Time Loop.

Second Chance from a Bad Ending in Fantasy Setting
https://myanimelist.net/stacks/36912
The side character is the Regressor/Isekai, the protagonist is not.
https://myanimelist.net/stacks/45493

Additional (currently no MyAnimeList page):
-(Manhwa) Second Life of a Gangster
-(Manhwa) My Younger Sister Was a Genius