Hi, this is a manga that I read years ago about this girl who likes a guy who is considered "plain". It takes place in a middle/high school setting where the two fall for each other and date. I remember there being multiple volumes so definitely not a oneshot.

Only other thing I remember is at the end, the two have matured quite a bit and have become a good-looking couple. The girl's friends were remarking that they were jealous because of how good-looking her boyfriend had became (or something like that). The girl also became popular because there a lot of guys staring/blushing when looking at her which annoyed her boyfriend.

That's all I remember but any information is helpful. Thanks!