"You're my sister but WHY do I fall in love with my own sister? Isn't it wrong?" - Huang Zitao

"Why MY HEART just beating whenever I'm with you? This is WRONG because you're my BROTHER," - Huang Ziyu

"Don't you see? He's YOUR BROTHER. Why don't you date with me? You know maybe your feeling are confused after go out with me?" - Zhoumi

Tao know that he shouldn't fall in love with his own sister but whenever he's with her, he feels so calm and warm around her.

Yu is scared that she know she falls in love with her own brother. She tries to make it go away but her feeling never ever go away. Futhermore, her feeling just pushed her more.

Why do they have to be like this?

Why their hearts have to fall in love each other?