When ML was young, MC's adopted "mom" took MC to work with her as she was filling in for a maid. After ML leaves to study abroad, MC's real mom brings An Nanyi (MC's adopted "mom"'s real son) over to ML's house to visit ML's mom (mother An & ML's mom are good friends). Even as a kid An Nanyi is a real jerk...he tried to force MC to do whatever he wants, MC refuses. An Nanyi gets up set and sneaks one of his items into MC's bag. An Nanyi then cries saying his item was lost...directs the adults to believe MC stole it.
MC's adopted "mom" who recognized An Nanyi was her real son, doesn't listen to MC's attempt to explain what happened...she says MC is a bad kid and has had a bad habbit/history of lying/stealing? anyways she slaps MC to stop talking. MC's adopted "mom" takes MC away and the situation is closed with them not being allowed back at ML's house...
kid An Nanyi is smirking/gloating about successfully framing MC