I suppose Nagatoro and the rest of the cool girls don't wear helmets as a measure of rebelliousness, because they're not stylish, or whatever other reason a teenager might come up with; though Yoshi is probably just following Gamo's behavior. For some reason, without glasses, Senpai's demeanor seems even more subdued. Nagatoro was being pretty light on him though, even after he rejected her invitation for the night time skiing. This is another chapter where it feels like Nao's determination is going in reverse, especially considering the last chapter; he's back to barely being able to look anyone in the eye while explaining himself, and doing so in the most sheepish, flaccid manner. How many times do the loyal wing-girls need to instill some confidence in him? You know you're embarrassingly bad at something, but the girl just keeps hanging out with you anyways, wanting you to have fun with the experience; catch a clue, Paisen.
These friends of Nao's though: I feel like it's practically impossible that they would have absolutely no idea about Hayase and her friends being involved with him on some level, especially during the art club competition. It's like the author just threw them in as an afterthought, without considering the history. Or, maybe it's just that I can't remember them ever being mentioned before; I didn't read through the 400 or so comments before writing this.