/jp/ - Otaku Culture

Loli or glasses.
But if I had to mention That one that is so specific that you can't even imagine how it came to be? Erm... I'd call it "casual exposition", or something like that.
I think the key factor is "seeing something that most of the time would be rude, but being in a situation where for some reason or other, the girl doesn't mind it or is focused on something entirely different".
Akamatsu is very good at this, pic related. That's a lewd pose, but the attention is focused on tickling, so it's not taken as a sexual thing (though I do so, very much).
Another example would be in the hot springs, where the girls barely cover themselves with a towel because "it's an onsen so it's OK". Or if they get surprised changing, when they cover only their breasts because the focus is not exactly in covering themselves, but in the surprise; that one instant is golden.
It's so... specific...