Koei Tecmo is planning to launch at least two big-budget video games in the relatively near future - Team Ninja's Dead or Alive 6 and Nioh 2, but it looks like the Japanese holding might also try to revive soon yet another once-great Team Ninja video game series - Ninja Gaiden, as the last major entry in this modernized slasher series was released on March 20, 2012 for both PlayStation 3 and Xbox 360.
Considering that it's been nearly seven years since the launch of Ninja Gaiden 3, it would make sense to remind players all around the world about the series that had been (in)famous for its difficulty long before FromSoftware's Demon's Souls. In their latest Tweet, Koei Tecmo announced "2019 is going to be a banger for games! Here at the #KTFamily we might just have a few surprises for you too!"
The Tweet also features a photo of a detailed Ryu Hayabusa statue, suggesting that the main hero of Ninja Gaiden might be getting ready to return in his demon-human hybrid form. The fact that Ninja is currently working not on one, two, but three announced projects (Dead or Alive 6, Nioh 2, and Marvel Ultimate Alliance 3: The Black Order), would make developing Ninja Gaiden 4 almost impossible, but there's always a chance that after DoA6's launch next month, DG4 will be their next big thing.