First idea, I had to think of was the 1st volume of
Kanpeki Kareshi Kanojo. It's pretty funny and the storyline actually deals exactly with the topic of romantic expactations, that become crushed and then advance into something more realistic. Kkk. So, it might be to your liking.
If you don't mind Manhwa, then
Hannune Banhada! Season 1 and it's sequel could be worth a look, too. Although the drawing style is probably not everyones cup of tea and the main character is somewhat hard to take by times, the storyline and dry reactions of the male counterpart made me laugh a few times. It's also dealing with the obsessive phase after falling in love and the awakening to reality then after.
Second Manhwa recommendation would be
You're So Cool, which is exactly showing your longed for scenario. The female lead is naive and falling for the most popular guy, but then comes to realize, that most people actually don't know a thing about his jerk-like personality and the reason behind all this. The developments are a bit predictable, but ... Well, it's a Shoujo.
There are tons more^out there, but maybe these aren't the ones being recommended often. ^^
________________
"It's like love is a bonus in your life. Even without it, I'm just fine. I don't feel like pointlessly searching for it. You don't have to make yourself unhappy." (Ookami Shoujo to Kuro Ouji)
"Why does it rain?" - "To create drama." (Drops (Andou Yuki))