Okay, this starts out in a normal guy living in an apocalypic world where he was hiding from a certain person who is know to cause the chaos. He was then found by her after unexpectedly trying to scavenge for food and was about to die yet he was then teleported to the past due to that person's power and his clashing and barely survive the attack.

He slowly unravels at how beautiful the past was and decided to find a way to change the future. But by accident of his arrival, he ended up causing his parents to not meet, he also cause the person he was trying to change to end up falling for him.

Due to not living a normal life, his knowledge in relationship causes even more chaos while also dealing with beings that once caused troubles from the past but was unimportance of how impactful the powerful being was.

How would he deal with a life he didn't have, dealing with normal things a survivor from the future barely understands and even having to battle out with monsters while at it?