tbh there's only 12cm difference in their height. supposedly irl that height difference would be very obvious. but author didn't really draw them that much obvious difference in height. though when both of them standing beside other people, they're towering them. seme is 195cm, uke is 183cm (yes I'm using cm bc that's what I'm used to).
their height gap is pretty huge, Touga is 188cm and Subaru is 169cm. but in the drawing their height differences doesn't look obvious for obvious reason.
more like size gap
I Didn't Expect a Scandal Like This