I've watched this "Keshigomu wo Kureta Joshi wo Suki ni Natta" both for Fukuchi Momoko (whom I dearly remembered from "Joshikosei no Mudazukai") and for the light-but-interesting premise.
The script is mostly brilliant, the cast did a very good job, the music - albeit not being my cup of tea - is totally fine, and the production value as high as they come.
So why am I not rating this higher than 8? Why not a 10 or at least a 9?
(Expect a MAJOR spoiler in my answer, so if you wanna avoid it, don't read any further! ^___-)
Honestly, I really didn't like the ending.
I think the story had been remarkably realistic (without being gloomy, thanks to the script, the funny side characters, etc.) until the last episode, and I found the kinda abrupt happy ending pretty off-putting. It felt, in all fairness, too unrealistic and predictable. The FL had been written, until then, as quite cold and seriously not being really into it much...then she reads the ML's letter from their school days, and *BAM!*, she suddenly melts and they live happily ever after? Big let down, sorry. Particularly since the script had been so good until then!
Imho they either should've taken more time (like, one more episode?) to portray her change of mind, or else, why not, they could've left it like that, as weird as it may sound; if anything, it would've given off a precious message: that is, that it's a lot more important to find someone who cares about you, rather than to waste your time running after someone who doesn't.
(Yeah, I know, it sounds harsh. But it's a pearl of wisdom from someone who's almost fifty and has been there, done that, and learned the hard way...^_^;...)