Board Thread:Speculation House/@comment-24177652-20140726065732/@comment-24616551-20140728092034

As you said, half-sisters. Yang was born to a different mother, and when her father married Summer, the father could have taken the woman's surname instead. Or perhaps Summer, in a slight act of rebellion and wish to keep herself as her own individual, had them each keep their own name. Hell, they could have never even gotten married.