Joseph Luster
June 27, 2020 
Ryoichi Koga’s Ninin ga Shinobuden manga—known as Ninja Nonsense in the west—first launched in MediaWorks’ Monthly Comic Dengeki Daioh in July of 2000, making next month the series’ official 20th anniversary. The original series ran until January 2006, but now Koga has announced the launch of a followup manga to celebrate the milestone.
Ninin ga Shinobuden Plus / 2×2 = Shinobuden + kicked off this week on KADOKAWA’s Comic Newtype website, 20 years after the start of the first series. Koga had the following to say about the return: “Since this is the first Shinobuden in a long time, I would be glad if you can enjoy it as a kind of extra edition, like ‘the chapter 0.’ I hope you will like it.”
After getting a bunch of positive feedback, he followed up, saying, ““Thanks for all replies for Shinobuden Plus! To be honest, I was pretty scared of what I would do if no one read it, but I’m happy that so many people enjoyed it. I’m glad I drew it… If you’ve not read it yet, please check it out from here.”
Ninja Nonsense was adapted into a 12-episode TV anime back in 2004.
Source: Ryoichi Koga on Twitter via Crunchyroll
