@Kllick Well . . . maybe. Surprisingly few that are that close, even though innocent good-hearted heroine + high-spec, somewhat initially cold male object of affection is very common in shoujo. But the thing is, a lot of them are not that well done, not really worth recommending. The best fairly strictly old school one I'm reading right now is Tsubasa to Hotaru; another, although annoying in places, with a fluffy heroine and pretty good is Tsubaki-chou Lonely Planet. I'm enjoying Sekirara ni Kiss fairly well too. I'm really liking Oogami-san, Dadamore Desu, which is interesting and steps slightly out of the typical shoujo comfort zone; the heroine is very self-conscious about her intense curiosity for sexy stuff, and the male lead avoids people because whenever someone touches him they blurt out whatever they're really thinking, which is often embarrassing. Preferably my Prince is a manhwa, not a Korean webtoon but a published print manhwa, and I tend not to like them that much, and like many manhwa it has some seriously grumpy characters, but unlike many manhwa it has a good heart; both the heroine and the hero are pretty good people and really, it's quite a nice slow burn.
Moving a bit out of standard genre but maybe more like this in spirit, and top notch in quality, there's Ore Monogatari. The heroine there is sweet and innocent as all get out, but the MC is actually the male lead, who is a good-hearted thick-headed massive gorilla of a guy, and his relationship with his best friend, a smart, deadpan very handsome guy that all the girls normally fall for, is about as important as the romance. It's sweet, wonderful, and very very funny and the art is incredible.
A couple of the fluffiest, cutest female leads in things I'm reading right now are in fantasy or historical style manga. Niehime to Kemono no Ou is very good if you don't mind the heroine being in love with the leonine demon king. Ookami-heika no Hanayome is about a prole girl acting as a temporary fill-in fiancee to the king in hopes of settling her family's debts and thickheadedly avoiding the realization that the king is totally in love with her and plans to make her the real deal.
Slightly more general recommendations because they're just awesome: Baby, Kokoro no Mama Ni! is very funny, it's from the male lead's perspective and he's too chicken to really start getting anywhere with the girl but it doesn't matter because the action is dominated by the most fascinating ugly toddler I've ever seen in a manga. And 3-Gatsu no Lion is a towering work of genius of which we are not worthy, by the incredible Umino Chica of "Honey and Clover" fame. Who would ever think that a manga about a quiet young teenager who plays shogi (Japanese super-chess) for a living would be the kind of thing where you just dip into a past chapter to remind yourself of one detail and suddenly find you've reread like three volumes without noticing? But most of the characters have this massive vitality about them, and, and . . . everyone should just read it, OK? (There are romantic elements but they only start working their way in much like halfway through)
Finally, if you don't mind walking the yuri side I suggest Cheerful Amnesia and Tamen de Gushi. Cheerful Amnesia is exactly what it says on the tin, totally lighthearted funny and cheerful--girl wakes up in hospital, other girl says "I'm your girlfriend", amnesiac girl's reaction is "OMG that is so great she is so hot I am so lucky!" Tamen de Gushi is . . . OK, it's my general opinion that an awful lot of Chinese stuff, whether manhua or perhaps especially webtoons, is crap. But the exceptions tend to be big exceptions; Tamen de Gushi is that exception. Both girls are so awesome, one massively boss cool (if mischievous), the other enchantingly, heavenly cute, with art so amazing I could just look at the pictures forever; meanwhile the comedy is hilarious, the feelings are sweet, the relationship is fun and interesting and touching, sometimes all at the same time, pretty much everything about it is bloody awesome.
Well. That was overkill.