Episode 12: The girls are fighting a Desertrians made of living water. When Cure Marine tries to punch it, she gets sucked inside. Chypre and Coffret manage to provide her a straw to breath through. When Tsubomi's ready to finish the monster off, the understandable concerned Marine freaks out over being in the crossfire. She does get hit by it and does the "Bwawawawaaaaa~" sound all Desertrians do when struck, only to fall out of the defeated monster, unharmed but heavily relaxed by the power that cures wilting heart flowers.
The entirety of episode 21, which is about Potpourri looking for the candidate of the third Precure. Reached to the peak when Kenji pretended to be a Pretty Cure, calling himself Cure Fire and after being told by Potpourri that he would make a good Pretty Cure, he imagines himself in a dress.
Episode 28 as well.
Particularly the part where Cobraja tells the Desertrians to the destroy the school, since they don't like homework. Marine chimes in:
Marine: Ummm...Could you do the middle school too..?
Coupe randomly appearing in the background and in the corner of the screen at various points in the second ending.
Itsuki's Unsettling Gender-Reveal to BOTH Tsubomi and Cobraja. The faces they make in reaction is just extremely priceless.
Continuing that on Tsubomi's case, there's also Erika Comically Missing the Point by 'cheering' her with the fact that the Fashion Club can continue, much to Tsubomi's disappointment.
In a Hilarious in Hindsight and Fridge Brilliance moment too, there's also the fact when Itsuki was training, and the other students were looking at Tsubomi for being 'too loud', the fact that their face is probably not telling her to be quiet because training is in session, but instead being amused that Tsubomi didn't know Itsuki's actual gender (and Tsubomi mistook their glare as 'be quiet, training is in session'... kinda counts too.
Blossom: (T_T) That's the second time my first love experience flies away...!
Every main Cures usually have troubles in adjusting their powers when they first receive it. However, in case of Blossom, it is just downright hilarious seeing her running around and being clumsy due to her massive flaws when under attack. Getting better is part of her character, but when she really was "The Weakest Precure In History"? That was comedic.
Erika alone is a factory of CMOF. Her genkiness is rather extreme that she's very prone to make awesomely funny face reactions or sorts, a reason why she's that much liked in the fanbase.