Birthmarks

Receiving a riddle from Xiao YuRin was like a thousand of needles piercing YuYan's mind. 

YuYan can't help thinking why does it have to be this way. It is not that she is not good with it, but it was confusing. 

Therefore, YuYan tried to contemplate in her thoughts but she can't help feeling irritated after not getting a response from Xiao YuRin. 

She suddenly blurted out. "What it has to do with birthmark? We are not the only one who has birthmarks.. All eight of us has birthmarks.." 

YuYan lowered her head while she tried to think until she finally realize. "Hang on… Only me and big brother Yun has different birthmarks, then you and the others were the same.." 

This is true. The entire siblings have birthmarks. The same six pointed star birthmark on their left chest, but only YuYan and Xiao FengYun has a different birthmarks.