If I remember right, she walked out on her sons life and left him with his abusive dad
Oh yea and then she came back when she heard the news after he had a rich and famous hubby I think.
She left hye-sung then the dad told her hye-sung hates her so she didn't look for him. Then she got remarried. When Dojin's wife and Baby pics got circulated she recognized hye-sung and contacted Dojin to see hye-sung but it didn't go cause she kinda shifted the blame to hye-sung by saying why he didn't look for her so hye-sung told her to get out and don't let him see her face ever
Didn't go well*
Can someone remind me what the grandma did again