I own nothing except the plot. If I owned Hetalia, I'd put some more background into Korea.

So, I hope you enjoy.

It was an old act, but one that no one ever saw through. That was the way it had to be. No one knew what could lie behind his facade, or even that it was there. They saw a happy-go-lucky, somewhat perverted, and well-meaning nation. What they failed to see was that it was a ruse. Not even Yao or Kiku, who spent longer with him than anyone else, knew. Alfred wouldn't notice unless it fell out of the sky and hit him in the face anyway.

Young Soo, despite his cheery appearance, was usually seething under the surface. For the most part, the other nations ignored him. He pretended to hate it, in reality, it was the opposite. The more often he was alone, the more often he could put aside his 'mask'.

That was the best way to describe it. He saw his facade as being like one of his traditional masks. Always frozen in an exaggerated grin, no matter the true expression of its wearer. Sometimes, he just wanted to rip away the act and scream at them all for being so stupid. He'd gotten dangerously close to doing so on multiple occasions, but not once did the guise falter. In a way, he was an actor beyond compare.

He was getting home from another fruitless World Meeting. His house was in a traditional Korean style, but was more modern on the inside. The grin stayed on his face until the door closed behind him. Afterwards it immediately disappeared, his following facial expression looked like he'd never been happy in his life.

He walked past the living room, his bedroom, he just walked to the room furthest from the front door. He wrenched the door open, he intentionally made it difficult to open. He grabbed a sword off the wall on the way in. It looked vaguely like Japan's sword, but more curved and much, much bigger. It was almost as long as he was tall. He carried it easily from decades of practice.

The room looked smaller than it really was, because one wall was covered in a couple feet of thatching, which had several layers of wood under it.

He gripped the sword tightly and rushed at the wall, driving it deep into the wood under the thatching.

He needed this. It kept him sane, helped him keep the happy pretense. It wasn't uncommon for him to imagine the sword going through China or Japan. He was just so fucking nice to them even after the fucking hell they put him through, and they treated him like shit.

He didn't lock the door to his house, no one ever came by anyway.

He didn't notice that he had left the room door open.

He didn't notice that Japan had come in the house while he was stabbing the wall.

He didn't notice until he was pulling the sword out of the wall again and was about to put it back up that Japan was staring at him from the doorway with a look of shock on his face.

The guise came up reflexively, "Japan! Did you need something da-ze?"

God, he hated saying 'da-ze'. Hell, most Koreans couldn't even make a 'z' sound.

Japan didn't respond. He saw Korea stabbing the wall. He had never seen the other Asian look so angry before. The sheer raw hatred that was in those eyes was somewhat frightening. And here he was, smiling as though it had never happened.

"A-America-san wanted me to ask you if you'd take him sightseeing," Japan said, quickly pulling himself together.

"Of course, da-ze! Mind you, you ought to tell him there's not much to see but temples and palaces."

"I'll make sure to do that." Japan was starting to think he imagined the hate in the Korean's eyes, looking at him smiling like that. But he knew he had not. And Young Soo's demeanor only changed when he realized Japan was in the room.

Japan quickly left Korea's house. America would be happy to know Korea would give him a tour. Japan also had the distinct feeling at least some of the others should know about what he had seen.

I have no idea what genre this is as the moment.

As for what happens next (on the off chance you like this), well, you'll just have to wait.