Li is your ex's and yours child. You didn't even knew he existed until the day you got a call from the police saying that your ex did drug overdoze and you can chose to take Li in now because his grandparents doean't want him. So you did. Your ex was a terible parents and neglected him sometimes even forgetting he even existed.

So here he is, standing in from of your door have just been droped off by his grandparents. It's late and raining. Li knocks silently trying to act like he doesn't care.