The Super Sentai Series (スーパー戦隊シリーズ) is the name given to the long running Japanese "superhero team" genre of shows produced by Toei and Bandai and aired by TV Asahi, that is used as the basis for Power Rangers. ("Super" refers to their use of mecha, and "Sentai" is the Japanese word for "task force" or, literally, "fighting squadron" and was also a term used for Japanese squadrons in World War II.) The shows are of the "tokusatsu" genre, featuring live action characters and colorful special effects. This series is one of the most prominent tokusatsu productions in Japan, alongside the Ultra Series, the Kamen Rider Series, and the Metal Hero Series. The first Sentai series, Himitsu Sentai Gorenger, in April 1975, was created by the late Shotaro Ishinomori, creator of Kamen Rider and Cyborg 009 in 1975.
Following J.A.K.Q., the second Super Sentai, Toei chose to work with Marvel Comics to produce the live action adaptation of Spider-Man (1978), which included the first giant robot in a Toei Superhero show. This concept was later used in Toei and Marvel's project Battle Fever J (1979), the third Super Sentai. The following forth Super Sentai, Denshi Sentai Denziman, was the first production solely by Toei.
All Sentai feature heroes that use a transformation call (referred to as a henshin sequence), a short phrase or sequence of words spoken just before or simultaneously with the transformation. The nature of the call varies from team to team but it is implied that the call must be spoken in order to successfully transform.