From episode 17, during her tennis match with Mylandah. The paragraphs below contain SPOILERS.

Many of the characters in Battle Athletes TV are stressed beyond their breaking points, but few snap as dramatically as Anna. I had thought she was an annoyingly meek character, so it was refereshing to realize that she came to the satellite with a dark secret. It was also nice to see meek Anna startle the super-aggressive and generally not very nice Mylandah a bit. :-)

Personally, I blame Anna's earlier "incident" squarely on her mother, who hammered the importance of going to university satellite and becoming Cosmo Beauty into their heads so often that Anna believed that was the only way to win her love. While Battle Athletes is specifically about sports, it contains many themes that are universal, equally applicable to academics or any other field of endeavor. This is one I imagine many of us can relate to.

I like the dramatic contrast between the red-eyed maniac and this sweet portrait. :-)