I'm struggling to understand Brun's thought process in assuming that a big person would be afraid of fewer things.
Brun's personal reality seems to have been founded entirely on binging on animé. Bearing this in mind, the whole idea of a bear-like giant of a man being nervous and anything but loudly bluff and outgoing would seem like a breach of the laws of characterisation to her. It is possible that one of the biggest journeys Brun has to make is to realise that you cannot learn everything you need to know about the world from the TV.
You sound like you're suggesting something ridiculous like that anime isn't real.
References aside, relationships, especially, are portrayed...literally everywhere. Practically every damn story, no matter the medium (and
especially in anime and videogames) is a (hetero) love story wrapped up in some plot like overthrowing the empire or something. You can go whole days, hell even weeks without seeing anyone pass the bechdel test
irl. Given the prevalence and popularity of "information" about the subject it would make sense to use it as a baseline for understanding - even if there's individual variance in specifics in real life, people would at least recognize and respond to the tropes, and it could go from there. It isn't illogical to think that media that is supposed to be a reflection on life could be useful as a guide to life.
Of course yeah it really doesn't work that way, it turns out that fantasy relationships are...well fantasy, and the way it ACTUALLY works is something else entirely unrelated. (I don't know what that is, though. People are weird and the things they do are often nonsense. Elliot's purpose last comic completely missed me, too, until Renee explained it.)