Ni-Oh (仁王, lit. "benevolent king") is an as-yet unreleased historical action video game with role-playing elements being developed by Team Ninja, to be published by Koei Tecmo for the PlayStation 3 (PS3).
Originally announced by Koei in 2004 (before their merger with Tecmo made them Koei Tecmo), the game is based on an unfinished script by legendary Japanese filmmaker Akira Kurosawa titled Oni (named for a type of Japanese demon). The game was to be released with a companion film, also titled Oni, that would have seen the directoral debut of Hisao Kurosawa, Akira Kurosawa's son. Hisao Kurosawa was completing his father's script with assistance from game producer Kou Shibusawa of Koei, with a combined production budget of ¥ 3 billion for both film and game. "When reading Hisao Kurosawa's script," Shibusawa said during a press conference, "it gave me the impression of stories like 'Seven Samurai' and 'The Hidden Fortress' -- I felt the common DNA between him and Akira Kurosawa." 
The first announced release date (with the new title of Ni-Oh) was summer of 2006. Although this was the first release date to be announced for any PS3 game, it was slated several months after the PS3's planned release in spring 2006, suggesting it was not intended as a launch title. In preparation for the 2006 release, a pre-rendered game trailer was shown at the 2005 Electronic Entertainment Expo, and a similar trailer was shown at the 2006 Tokyo Game Show.
The game missed the initial 2006 release window without comment from Koei. It wasn't until 2009 that Koei confirmed that the game was still in development, apologizing for the lack of updates. In 2010 Koei (now Koei Tecmo) announced that Tecmo's Team Ninja would be finishing development of the game, which had been suspended by Koei. In an interview with Siliconera, Team Ninja head Yosuke Hayashi described their vision of the adopted game:
We ran lots of tests and trials for Ni-Oh. After we ran through these we found a style that fits this title. At Team Ninja, we want you to experience the feel of action in our games. Ni-Oh is set with during the samurai era and we want you to feel what it’s like to be a samurai.
— Yosuke Hayashi
In August 2014, Koei Tecmo filed a new US trademark for the game. In a November interview with Venture Beat, Hayashi confirmed that the game was still in development and that "it is starting to come together and feel good."
- "Koei, Kurosawa Team Up For PS3 Game: News from 1UP.com".
- "Kurosawa Comes to PS3 - IGN".
- "KOEI Shares Ni-Oh Release Plans - IGN".
- "Official E3 2005 Trailer (Remastered) - NioH (PS3) - IGN Video".
- "Ni-Oh - TGS 06 Show Floor Trailer | Gametrailers".
- "Years in Development, This PS3 Game Still Lives. Well, Apparently".
- "Eagerly Awaited Koei PS3 Title Still In Development".
- "Team Ninja Reveals Its Next Games: Ninja Gaiden 3, Ni-Oh".
- "What’s Next For Team Ninja? The Short Answer Is Ni-Oh".
- "Koei's Ni-Oh still alive?".
- "Balancing isn’t easy: Team Ninja on Dead or Alive 5: Last Round in the competitive scene, sexual fantasy, and the future".
- Original announcement from October 28, 2004 (in Japanese)