honestly? i don't drink so i don't know....
but the world is a vast place, who's to say there's not somebody out there with no tolerance for even 1% alcohol? 7 billions is a big pool to test from...
frankly, i don't know or even care to know...
plus it's kinda a trope joke in japan/manga for underage to get drunk from them i guess.... 20y/o is their age limit for alcohol too iirc...
I laughed how he considers drinking with Nagatoro when they're older and instantly realizes why that's a terrible idea. I fucking lol'd.
Mate, Nagatoro ain't gonna mindbreak or give into NTR. She's the type that breaks you. The closest you would ever get is if her "Sempai" got assaulted by her friends, but whatever Nagatoro would do to them after that, you wouldn't recognize the bodies as human.