Better than the first

So now, Young Jo and Yoo Kyung are involved together. I am sure that Yoo Kyung is after him because of greed since she knows that he's the heir and less importantly because she found out that he was Eun Jung's first love. I really can't find a reason why she hates Eun Jung that much, I know that she transferred schools and got a scar partially because of her but that's about it. She doesn't need to be a hater because of that to the extent that she would cut her off from being an actress.