Who is Ruby Rose's father?
TaiYang Xiao Long is both Yang &amp; Ruby's father.

Yang's mother is unnamed as of Season 2. Ruby's mother is Summer Rose, who is Yang's step-mother.

I have two theories as to why Ruby is Ruby Rose not Ruby Xiao Long.

Theory 1

Summer Rose was insistent that her name be carried on, and so Ruby was given the surname Rose. As Memor-X has said in the comment, a husband taking a wife's surname isn't all that rare nowadays.

Theory 2

It was a convenient choice for the writers - Ruby and Rose are both very vividly red items, whereas Yang Xiao Long can be translated as Small Dragon of the Sunshine or Little Sun-Dragon, reflecting Yang's powerful, fiery personality &amp; battle ability quite well.

Theming the characters with their colour seems to be quite important in RWBY - For instance, check out their pajamas below - Yang has a fiery heart on her tank top, whilst Ruby has rose-patterned bottoms.



I suspect we may find out more if/when Yang's mother's identity is revealed.