User blog comment:Godisme/Keen Marker/@comment-919115-20110302175318/@comment-5044191-20110308223912

Rh73 commented about the girls in Bleach, and I thought I should have brought that up.

In any case, until we get a good reason other than the fact Riruka was, ahem, cursed with Fullbring, we can only assume Riruka was most likely born that way, or when she learned about her powers, she became ill-tempered and basically Hiyori's clone.