I wouldn't call it "city pop". these are almost all by a guy named Hiroshi Nagai. he's the only one doing this specific style.
everyone who likes this definitely needs to go check out all of his work. unfortunately there's no good central collection of all his works in high resolution. I know he has an artbook available but it's quite expensive.
i have
>>7586914and this one printed on canvas on my wall. I had some website do it because he doesn't sell them
also he did the art for this album which is really good and sounds like the paintings
https://www.youtube.com/watch?v=IyyyfEcsULQ