It's very military.
A lot of fans have been commenting, complaining, making fun of, etc, etc, about KyungSoo's haircut. I personally don't see anything wrong with it. To me, he wants to be taken seriously as an adult and so he dresses and grooms himself as so. But over the last year, he seemed to be dropping hints about something.
Could it be he got his draft slip?
On the guys' V live bowling competition, they all commented on how KyungSoo has been wearing a lot of green, a lot of military green. Although, he's been keeping his hair short like this for a while now. Once your military draft comes in, that's it. From what I understand and have seen in the news about other idols getting drafted, is that their companies, whomever they're with, will try to push it off as much as they can. It's not necessarily the oldest that's going to be going first. It could be any one of them, at any time. As long as you're finished with high school, you're good to go. Keep in mind, South Korea is still at war with North Korea. I don't think anything should hinder their enlistment. They are doing something good for their country by learning to defend it. It shouldn't be something to run away from.
Kim Hyun Joong got his draft notice in October 2014, but he postponed it. He didn't go until March 2015.