Board Thread:General Discussion/@comment-3257939-20131104060426/@comment-14202062-20131104231354

Yeah, I agree with the thought that Yang is singing a lullaby to Ruby. It just seems fitting, what with the rose references, the title of the song (which fits with Yang), and the lyrics in general.

I mean, you can clearly tell that Yang is the one singing the song; attempting to comfort Ruby by stating that she'll always provide her with joy and happiness. After all, they are sisters, so it's their duty to look after each other; more specifically Yang's duty to look after her innocent and younger sister.