The (wholesome) Whiplash of manga.
In all seriousness, this is very touching. Not only is it based on a real, lived story, but it's told so achingly, it's so heartfelt, that you can't help but compare it to your own struggles, can't help but wonder "what would happen if...", and in general it engages you so much more than a common work of fiction could do. Higashimura Akiko is a genius.