User blog comment:B214/Light Novel Volume 16 spoilers/@comment-9339850-20131018161752/@comment-16281343-20131020110432

hmm.. if your theory is true..

What if both of the sisters' true form are lolis? And they transform/ grow when they are activating or using their senjutsu power?!

If so, that will be a great piece to make a short story from.. Kuroka unable to use her power and returning to her original form.. which is a girl with a loli body!!