1 Work in Heroine - James O'Rell
A story that takes place right before Grimjow's attack on Karakura Town. It brings three characters from the book Heroine (which is the first (and currently only) book in the Chronicles of Autumn series) to Karakura Town to help take on a new threat that is pulling Aizen's strings. The world these three characters from Heroine are from is just like our own, meaning Bleach is an anime and manga one of the characters is very familiar with. Even with these new characters, it is very much a Bleach story, in Bleach's world, with a few totally new characters added in to mix things up.
Reading Heroine is helpful, but not required. Heroine can be found on Amazon Kindle for the curious http://www.amazon.com/Heroine-James-ORell-ebook/dp/B00BNUX4HC There is an FAQ at the end of the file that answers many questions if one doesn't want to read Heroine, but still wants to enjoy the story. But, reading this will likely give away Heroine's ending.