Definition: The world of humans.
A term from the tokusatsu series Garo. This term first appears in Garo ~Soukoku no Maryuu~. Probably created so that there's a term for the world of mankind compared to Makai which is used to describe the world of demons.
Ningenkai 人間界 or Ningen no Sekai 人間の世界
Used in Go-Onger and other shows. Just means "the world of humans" or literally "Human World" in some cases. In some cases, is used to describe separate dimensions ("the dimension where humans occupy" versus "the dimension of the alien invaders" for example)