Lead with extreme past experiences everyday ordinary life

Like maybe the lead grew up in a different country which was war torn and becomes a child soldier then when they're 18-19 or whatever moves to a peaceful country and has to adapt to an ordinary student life with bullies who doesn't know better that the guy who they wanna bully is someone who has killed for breakfast, or someone who has experienced an extreme trauma but acts as if everything is fine and everyone thinks they're fine, but are shocked beyond belief when they find out what happened to them, or similar. 

https://mydramalist.com/24919-okusama-wa-tori-atsukai-chui

• Innocent Love: The female lead has a traumatic childhood experience with her family that her brother is in prison for. She has to move to be able to live normally since the public shuns her.
• Missing You: The female lead is a victim of bullying as a child and the male and female lead have a traumatic experience because of it together. They meet again as normal adults.
• W: The male lead experiences a traumatic event involving his family and becomes a successful businessman later.