Thirteen is too young to gain eight years of memories that might come to pass--especially when you don't even know what to do with yourself in the present. But when the future is that bloody and dark, do you have any choice but to try to change it? He remembers the absolute agony of the doctors trying to save him, which finally sent him into blissful unconsciousness— —except he doesn’t remember any of that. Tsuna’s last memory is of putting his head down on his desk and falling asleep to the sound of the teacher’s droning, thirteen years old and tired of not understanding a word, not of being twenty-two and beloved and dying.

Nie Mingjue would be the very first to admit that devious plotting was not his strong suit – but if it meant he could make things better, make it so that his brother never had to dirty his hands to avenge him, he would do his best. His best, in this instance, was a forbidden ritual that sent him back in time to before their father had died, before Wen Ruohan's perfidy was revealed, before Meng Yao was twisted by the world's cruelty, before Wei Wuxian was orphaned... Nie Mingjue had a lot to do and very little time in which to do it. Best to get started right away.

Nie Huaisang thought that - should the time travel array actually work and he end up back in time before everything happened, with his brother still alive and well - that the first thing he would do would be to properly weep and cry and hug his brother, not jump straight into explanations and strategizing. Then again, he hadn't expected that the array would somehow send his spirit into his brother's body, casting his brother's spirit into his own past self, either.

Where Class 1-A finds itself in a time loop centered around their first year at UA. After getting over the usual angst, they decide that the best way to grow as heroes is by antagonizing dangerous villains for fun and amusement.