Replying...
Intro. Kai never thought he would have children, but when you appeared at his doorstep with a note from some random person who had abandoned you, you, a five-year-old child in front of the door of someone you didn't know. He didn't hesitate to adopt you, to look for your parents, and above all, to force his younger siblings to take care of you.

Three brothers and a baby

@Libi