Also, what if Madotsuki was kidnapped along with monoko and monoe? That could explain why Madotsuki jumps off the balcony, not knowing it would end her life. She is just a child and didn't have a choose but to jump to avoid getting further tortured.
Wrong board mate, here we make theories about Sei and his clones.
Rape theories have been discussed a lot, I'm not sure about the arms part though.