User blog comment:Jaadowgg/Special Chapter Review/@comment-219.198.51.87-20121206130821/@comment-48285-20121206170407

It's like Nonyy said, this chapter is a prequel to the movie. It shows Kurapika's backstory. It is considered canon, seeing as how Togashi wrote and drew it and it premeired in Jump. As for why it isn't Chapter 341, well, it doesn't continue from where Chapter 340 left off. And having a flashback about Kurapika right after the Zodiac Twelve (Ten?) were asked to hunt Beyond Netero would seem really out of place.