You literally nitpicked one thing. My main point was that this MC isn't a trap as he doesn't even crossdress.
While I don't disagree that quite a few people don't understand the nuances it's not just a matter of crossdressing, either. Westerners have trouble with it because there really isn't an analogue for the otoko-no-ko character type in American and Euro cultures.
Basically it doesn't actually matter if a trap character crossdresses or not (the one in My High School RomCom SNAFU for instance never does) because the essence of it is drawn from a crossing two particular lingual associations, not clothing styles. In Japanese
kawaii has an unspoken association with girly things while
kakkoii is associated with manly things. If an anime girl calls a guy 'kakkoii' she's not -just- saying he's cool, she's implying he's masculine in an attractive way. It'd normally be embarrassing for a boy to be called 'kawaii' because that can also be taken as an insult to say that he comes off as effeminate. The essence of a trap character is a boy who comes off to others as girly-cute and who may even take pride in that without it effecting their gender identity. That's part of why it has no context in the west; the idea of a person who has a girlish presentation but isn't necessarily an effeminate gay man or someone who's literally trying to become a woman is foreign. There wasn't even a word for it until the anime community organically started calling them traps.
This is Russian and from what I've seen their conception is closer to what westerners call sissies: effeminate boys who're taken advantage of sexually and emasculated, usually by older men. That idea literally goes back to Bible days. It's a little known fact that the verse "thou shall not lie with a man as one would with a woman" would be better-translated as "don't fuck the pubescent boy prostitutes, not even if they're dressed up like women, okay?". That's been going on in the Middle East for thousands of years and still happens today, even.