Team Ninja (Japanese: チームニンジャ) is a Japanese video game developer, and a division of Koei Tecmo, founded in 1995 as a part of Tecmo. It is founded and formerly led by Tomonobu Itagaki, later by Yosuke Hayashi, and is best known for the Ninja Gaiden action-adventure game series and the Dead or Alive fighting game series.