There has been a tokusatsu sentai
, or "task force," show airing ever since the first season of the show, Zyuranger
, aired in the early 1970s. Unlike Western series, however, the sentai shows typically reinvent themselves with each new season—bringing in an entirely new cast for a new continuity. Each season is about a different kind of ranger group, based on a different theme of powers or mecha
. Ninpuu Sentai Hurricanger
involved a ninja theme, Bakuryuu Sentai Abaranger
involves dinosaurs, and so on. The shows cross over only rarely, in TV specials or movies, and usually the crossovers
are considered "out of continuity
" as regards the main shows.
Sentai series titles usually involve three words, using the scheme "Adjective Sentai Adjectiveranger". For example, Ninpuu Sentai Hurricanger means roughly "Ninja Task Force Hurricane Ranger" ("Hurricanger" being a Japanese-style contraction that merges two words into one); Bakuryuu Sentai Abaranger means "Exploding Dragon Task Force Rage-Ranger" ("Abaranger" is a contraction of "Abare" ("rage") and "Ranger"). However, some sentai titles are exceptions to this rule.
One of the conventions of the sentai series is that the characters' costumes' color schemes relate to the characters' personalities or roles. Red is usually the leader, Blue the scientific or curious member, Green the Outsider, and so on. Though there are exceptions, the costume color schemes usually hold true throughout most of the sentai seasons.
In terms of storyline, most sentai shows are very similar, with only minor variations. Some supernatural or alien entity poses a threat to the Earth, and a group of otherwise ordinary people (usually five, but the most recent shows have started with three) who just happen to know martial arts are chosen by some Higher Power to become Rangers and defend the planet. Along the way, a mysterious outsider who has gained Ranger powers by some other means joins the team (possibly after first fighting with them), and together they battle the evil forces of their adversaries.
Usually, sentai adversary groups consist of one or more elaborately-costumed arch-villains who send equally-elaborately-costumed henchmen out to fight the Rangers (usually one per episode, though occasionally more). These henchmen have at their disposal groups of lookalike, unintelligent, faceless mooks, who will attack the Rangers one or more times before the main battle. They pose almost no threat to the Rangers even in their uncostumed identities, and serve mainly to provide an excuse for more karate action and/or Rangers to use various flashy attack powers. After the mook battles, the henchman will attack the Rangers, and sometimes get the upper hand until they use whatever new attack powers they've come up with for that episode and destroy him in showers of sparks and explosions. After that, the arch-villain will resurrect the henchman by growing him to giant size, so the Rangers can bring out their combining giant robot mecha to fight him. They destroy the henchman again, with flashy attack powers, and he usually stays dead this time. And so it goes until the end of the series, when the arch-villain finally runs out of henchmen and has to face the Rangers himself.
Although CGI has come to play a bigger role in recent sentai productions (especially for Ranger and mecha transformation sequences), most sentai battles (both between Rangers and henchmen and between Ranger mecha and giant henchmen) are filmed the old-fashioned way: with actors in rubber suits slugging it out, sometimes amid model buildings. And because those costumes can get pretty expensive to make, almost never is a Rangers costume or henchman seen to be physically damaged; instead, damage is symbolized by showers of sparks appearing whenever one combatant lands a solid blow on another combatant. When Rangers take enough damage, they often transform back to their human identities.
Though the first few seasons of Mighty Morphin' Power Rangers were strictly American productions based on costumes and stock footage of old Japanese series, in recent years Saban and Toei, the producers of the American Power Rangers and the Japanese sentai, have begun working together, even filming on some of the same sets, so that each season's Japanese sentai will become the next season's American Power Rangers.
Though tokusatsu shows have remained largely out of the fandom limelight, in recent years digisub groups such as TV-Nihon have taken it upon themselves to start fansubbing various sentai series (as well as other Tokusatsu, like Kamen Rider). Sentai DVD sets are also available through eBay and other online vendors, though they are usually Chinese bootleg editions and the English subtitles on these sets are usually badly-translated Engrish.