Responses
I'm guessing that if Takemichi changes the future enough, the events leading up to that wouldn't happen and he'd be transported to a totally alternate future. I think something like this had happed before where both he and Hina's younger brother had died, but he went to change the future.
So we know that b4 takemichi time leaped back 10yrs, he was hold Mikey’s hand for dear life on a tall building but because he gets into a coma like state when leaping back in time, wouldn’t he let go of Mikey’s hand because he’s unconscious? And because of that, is there a possibility the present mikey might be dead? Unless in later chapters both were brought down safely by like the fire department…