I posted this last night but I realized the topic isn't as general as it needs to be, so I'm posting it for what I am really looking for, a fantasy novel with a clumsy female lead. Though watching The Quest is what made me think of it 😀

OP: This is going to be a bit of a strange request, but I just recently watched the show The Quest (which is a reality show), and I really liked the idea of characters in a book like Bonnie and Sir Ansgar, possibly romantic. Does someone know a fantasy novel like that? Sort of a clumsy female lead and this stern guy, because in the show she's trying to become a hero along with other contestants and he's a stern warrior in charge of training them into true heroes and even though he's stern (and although he's an actor) you can tell he develops a soft spot for Bonnie because she has such a great heart-character development would be a plus. Thanks for reading and sorry for the strange request >.<

Stray Dog This almost fits your description perfectly.
Aoki Umi no Torawarehime Another that seems to fit.

Oishii Kankei Although this isn’t even close to fantasy, it was the first manga I thought as far as the type of relationship you wanted, so I included it just in case.

So, I’ve gotta say that the only actual clumsy female lead is in Stray Dog… because somehow I missed the first paragraph of the post until now LOL! 😔 But all of the MCs do have that heartwarming quality that wins people over, which you mentioned in the OP, and the males were close too. Sorry all I found were those two, and they aren't even novels.

Watashi no Ookami-san but it isn't novel

The closest in novels that I know of are
Miao Miao Miao (Novel) heroine isn't exactly clumsy... more like plain stupid in the good sense of the word. There is OP male lead that get her straight.
I Reincarnated into an Otome Game as a Villainess With Only Destruction Flags… (Novel) reverse harem with really clumsy and "dokan" heroine.
Otome Game no Burikko Akuyaku Onna wa Mahou Otaku ni Natta (Novel) similar to the other otome novel however the heroine is more balanced and isn't plain stupid. Just a bit from time to time. Is being manipulated by the male lead