News from Anime News Network, story which not told in Yusei Matsui's manga, which also has TV anime & live-action film.
In 2014, the 34th issue of Shueisha's Weekly Shonen Jump magazine announced last Saturday that Yusei Matsui's Assassination Classroom manga will be having inspiring a second event anime at this year's Jump Special Anime Festa tour.
What to expect on the 2nd event?
Expect a revelation in the story that did not appear in the original manga which features "that character and Koro-sensei...!?"
According to the same source, Viz Media will be responsible on publishing the first volume of the manga in North America in December.
Viz Media said that story:
"A humorous and action-packed story about a class of misfits who are trying to kill their new teacher - an alien octopus with bizarre powers and super strength! The teacher has just destroyed the moon and is threatening to destroy the earth - unless his students can destroy him first. What makes things more complicated is that he's the best teacher they've ever had!"
Jump Special Anime Festa is reportedly will visit six cities this year: Tokyo on November 9, Sapporo on November 15, Sendai on November 15, Osaka on November 16, Nagoya on November 16, and Fukuoka on November 16.