Unfortunately, this series was abruptly cancelled. So while it says Volume 1, that's actually all there is. The mystery of the story was never really resolved as to why he awoke as Aki. Then the last 30 pages are some 4koma that seems to be filler to pad out the tankoubon to 180pgs. Basically an alternate retelling with genre trope fluff.
The basic premise is he died, but for some reason he wakes up as Miyabe Aki standing in front of his casket at the memorial service. Except he has no idea who this girl is or why she came to his memorial. If I remember correctly, he then comes across a guy at her school that he used to be friends with, but then was bullied horribly at some point before going to another school. The guy shows interest in Aki however, through which the MC is able to find out that he actually felt really shitty about what he had done to the MC back then and for the years after that he never did anything like that again and would actually help others out. So MC is in an Odd Couple kinda predicament with him in that he wants to hate him, but finds he can't.
I assume the eventual plot was going to involve the MC becoming attracted to him as Aki and them dating or something, but it obviously never got that far. (At least based on where these kind of trope situations go in the genre)
Not sure if the names are right, but it says original story is: Morita Ayaka 森田彩加, art by: Oshizuki Roku 押月禄 Artist twitter: @oshiduki