I'm only on episode 1, but the part where they're in the taxi home and then especially the part where she's on the train thinking about being alone and her life being boring, I didn't like the OST. I'd rather just hear her thoughts without sad music, like don't try to tell me it's suppsoed to be sad with sadness music - her thoughts and the images of her going about her day were more than enough on their own. I'd rather it respected her life experience's in-built poignancy rather than distracting from it or sending a message of "her feelings are not valid enough on their own", by putting sad music.  Plus the music has vocals, which just made it distracting.

This is something I like in Japanese shows...bit more silence.

edit: alright watched 10 eps and it's not fine after ep 1