Update: Shacknews has acquired the whole of Itagaki's statement regarding his departure and legal action, viewable here, in which he apologizes to fans of his games and calls the social responsibility of Tecmo into question.
The director further revealed that, as expected, he will not be involved in any future Ninja Gaiden or Dead or Alive titles.
Original Story: Mere hours before the North American debut of Ninja Gaiden II, director Tomonobu Itagaki announced that he will leave Team Ninja and has filed suit against parent company Tecmo and president Yohimi Yasuda for unpaid bonuses and emotional damages, according to 1UP.
Citing "unreasonable and disingenuous statements" made by Yasuda and unpaid completion bonuses for the development of 3D fighter Dead or Alive 4 (360), Itagaki claimed damages of 148M Yen, roughly $1.42M at current exchange rates.
"When the time came for the [completion bonus] payment, Tecmo Co., Ltd. went against its previous agreement and refused payment," Itagaki said in his statement. "President Yoshimi Yasuda chose not only to violate this agreement, but also turned defiant, telling me 'if you are dissatisfied with the decision not to pay the bonuses, either quit the company or sue it.'"
"He made demeaning remarks about me to my subordinates and colleagues, causing me significant emotional distress and worsening my personal relationships and work environment," Itagaki added.
Though Itagaki has regularly helmed the Ninja Gaiden and Dead or Alive franchises at Team Ninja, the properties remain wholly-owned by parent company Tecmo, making future Itagaki-directed installments unlikely in the wake of his resignation and lawsuit.
"I regret the circumstances that have forced me to leave Tecmo, where I had worked for so many years, and I regret the disappointment this will cause my fans," Itagaki stated. "However, I can no longer continue to work with President Yoshimi Yasuda, a man who chooses not to honor promises even when he is able to do so. I truly hope that nothing like this happens again in the future."