I am aware of some changes that happend in 2018... and that is that men can no longer wait so much.. they have to enlist before they turn 28. Before it was up to 30. The age to enlist is now from 18 to 28 and men have to serve for a minimun of 24 months, though I read that in 2020 they will be dropping it to 18 months.
So answering to your question it is okey for both, Eungi and Jeongwoo to have enlisted on their early 20s. From what I've read some training are pretty harsh so the sooner you enlists the better.
Oooohhh so that's how it is. Well I also think that it's better for them to enlist early anyway. And thank you for that information! (≧∀≦)
I have a question.... and also I’m shamelessly recommending you to read this http://www.mangago.zone/read-manga/fools/ if you haven’t! Lol ヾ(☆▽☆)
Anyway, in Fools, both Eungi and Jeongwoo enlists in military at their early 20s. I’m not Korean, and I know that military enlistment is mandatory to every South Korean male, but as far as I know, they can enlist at least before they’re 35 yrs old right? So I was wondering why colleges students decided to enlist while still in their early 20s?