This imagines a futuristic dystopia where everyone was given the power of "redo" - the ability to rewind time and possess their own younger bodies in the past at any time (through magic or technology, doesn't matter).
The world is split between those who refuse to "redo", those who are addicted to "redoing", and those who try to "redo" only under the correct circumstances.
Imagine a world where at any time you or someone you know could be possessed by a version of themselves from some future you will never get to actually experience, people behave erratically as they undergo extreme shifts in personality and behavior seemingly at random, the series would focus on the effects this kind of thing would have upon the greater society.
For one thing, history has been completely lost, nobody even knows what year it is, as people have been "redoing" since forever.
The widespread power of "redo" is shown both positively and negatively, it acknowledges the good and bad of this world, some stories are heartwarmingly wholesome, others are grim scenarios for anyone who knows the truth, etc.
"Redo" is explored as a concept, not just for practical consequences but also psychological effects on people and the greater philosophical crisis that occurs in a world where one's mistakes could always simply be undone.
The story would follow five people whose stories intersect the central character being a thoughtful introspective sort or adamantly refuses to ever "redo" as he seek