Separated by a wall

Noah is a 9 year old who loves to explore. There's nothing odd about him. But one day he wakes up to find himself and everyone around him has blue horns. As everyone starts to freak out Noah runs outside after looking through his window to find a massive wall between his hometown. He's inside of a box with no escape even after running for miles.
On the other side of this box however is another where everyone around a misterIous and quiet boy named Kai has red horns except him! As everyone is freaking out about the wall and the horns fights start to break out and Kai is left to run and find shelter.
Meanwhile as everyone starts to calm down on Noah's side someone mysteriously finds a gap in the wall where the two party's got together. Once they reunited someone went in for a hug and the person with blue horns died by a spike flew up from the ground impaling them in seconds. There no survival. Quickly people start to learn that if a person with red horns touches someone with blue horns the person with red horns dies and the person with blue horns stays. It was unanimously agreed upon that the two party's where to split and never see each other.
7 years later Noah is 16 and one day decides to go to the other side and see what happens. Once through the gap Noah meets Kai and instead of kicking Noah out he gushed him away into a secret base where kai was trying to figure out this whole mess.
So do you know why all this happened or who is to blame? Read through and watch as our young protagonist and Noah learn more about the treacherous, and bone chilling events to why the walls there and what about the horns. Watch as they start to fall in love not knowing the consequences.