Here is what happens if you raise V4's arms up. Her breasts start to poke through the bra. That's caused by the Joint Control Morphs (JCMs). In this case, a raised arm uses a JCM to pull up her breast in a natural way that follows the arm movement, but the clothes cannot follow those changes.

I'll post an explanation of how to fix this a little later.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)