... It's really not that great.
It's above average (anything above a 5 is above average - people on this site struggle with understanding 1-10 rating systems; a 5 is the top of the bell curve meaning most normal/average manga readers will still enjoy it even if it's not peak. Rating something a "1" just because you think the current aggregate rating is too high is ridiculous as you will have only a negligible effect on the aggregate; it's better to be honest).
It was enjoyable to read, but not to finish because it feels extremely abrupt, with your classic vague ending that Japanese authors seem to love so much. There are hidden cultural indicators such as...
the ceremony they are attending at the end is for 20 year olds in Japan, specifically people who turned 20 in the last year or people turning twenty very soon, meaning they kept in touch for several years even though they both went to different cities for post-secondary education/training).
Deaf people get pretty much zero airtime in manga or anime. This isn't really a problem because then you run the risk of putting pressure on mangaka to include character types who are highly likely to end up defined by things other than their character and behaviors, potentially becoming poorly-written stereotypes rather than independently interesting on their own merits (although, realistically, manga and anime thrive on character stereotypes, but not ones that are insulting to a disability demographic). This manga by its very nature avoids that, making Shoko's deafness key to the way the entire story plays out.
As a manga generally, it just doesn't rise above the pack of other "above average" manga. It's fine but that's it.