WARNING: The following contains spoilers for Episode 12 of Tropical-Rouge! Precure, "Confiscated! The Aqua Pot's Not Allowed?!" now streaming on Crunchyroll.
The Pretty Cure franchise is no stranger to non-human main characters, from the fairy-cat-turned-human Siren of Suite Pretty Cure to Yes! Pretty Cure 5 Go Go's toeing of the line by allowing every mascot a human form. But usually, these characters -- unless also a Cure or Cure-equivalent -- don't really have any spectacular abilities of their own... until now.
As a mermaid, Tropical-Rouge's Laura is able to do a lot of things other series mascots can't, like giving full hugs, breathing underwater, and more likely than not, easily benchpress her own body weight. As Episode 12 quickly reveals, while she may not appear to have much muscle on her body, Laura is lot stronger than her physique lets on -- all thanks to living on land.
Laura's feats of frankly absurd strength begin halfway through Episode 12. With the school's Disciplinary Committee dead-set on putting an end to the mermaid rumors around school by conducting random searches of clubrooms, it was only a matter of time before they caught the Tropical Club unprepared. Due to their sudden entrance, a wayward skateboard and the Mermaid Aqua Pot flying out of Manatsu's hands, Laura is forced to hide the only place she can: behind a blackboard three feet off the ground. Not only does Laura manage to hold on with just her hands, but she's able to keep her tail out of sight while also holding up Kururun!
It's implied that not only does she hold on, but she goes completely unnoticed by the Committee throughout the rest of the search. Even the strongest human athletes would have difficulty mimicking her pose for more than a few minutes, let alone doing it silently.
As if this no-doubt adrenaline-fueled feat weren't enough, Laura tops it later in the episode. When the Mermaid Aqua Pot is confiscated, Laura is forced to retrieve it on her own thanks to the untimely appearance of a Zenzen Yaran-da. But, being a mermaid traversing the school by skateboard isn't exactly... subtle. Thus, she's almost immediately spotted by the Disciplinary Committee Head, Masami Kakuta, who rushes into the room. With moments to spare, Laura grabs a uniform confiscated for an against-regulation skirt length, and stands up, stuffing her tail fin awkwardly into a pair of shoes.
Not only does she hold this pose without so much of a hint of discomfort, to the point that Masami doesn't question her humanity, but she manages to then jump to the top of a shelf to grab the Pot, and then out-speed-walk Masami so that she can have an opportunity to enter said Pot and escape.
When one considers that Laura's fins are depicted like the soft veined fins of a fish, her ridiculous strength becomes even more confusing. Most fish fins have very thin bones that, while not exactly delicate, would most certainly crumple if asked to support said fish's entire weight -- especially since, rather than the thick flesh of water mammals, fish fins tend to have simple protrusions of skin covering these bones, not unlike a bat's wings or the webbed toes of a frog. In contrast, not only are Laura's fins nimble enough to fit into shoes, but they're strong enough that she can speed-walk in them, to say nothing of her near-perfect balance on what we have to assume is her first try.
But how did she get so strong? Is her strength just normal for a mermaid? Well, yes and no. Laura's strength is most definitely normal... for any mermaid on land.
Having lived at the bottom of the ocean her whole life, Laura has not only survived depths that would crush a human but also strong ocean currents, essentially enduring full-body resistance training her whole life by constantly moving through water. By moving up to the surface and from moving through water to air, Laura has made just moving significantly easier for herself by reducing the resistance her muscles have to cut through to do anything.
But despite her environmentally-induced super-strength, it's still clear that her body wasn't built for life on the surface, with her fins being an entirely impractical mode of transport. Instead, a much easier (and cuter) option would be to stick with the skateboard she and Kururun used throughout the episode -- because who doesn't want more skateboarding Kururun in their life?