A particular franchise that's benefited from the way '90s nostalgia has permeated the lives of millenials everywhere is Power Rangers.   Celebrating its 25th anniversary this year, Power Rangers is riding high. Though the film didn't do especially well, people still love the show, and its comic book over at BOOM! Studios is particularly well-acclaimed.  It's even got a special event coming this Spring in the highly anticipated "Shattered Grid", that should last well into the summer.

But did you know that Power Rangers was directly based on a Japanese series? Called Super Sentai in Japan, the franchise was created by the anime juggernaut Toei all the way back in 1975, and existed for 15 years before Haim Saban finally turned it into the series featuring teenagers with attitude that we all know and love. But Saban actually tried for seven years to get someone to pick up Power Rangers as a show before it finally got the greenlight in 1992, meaning we were robbed of several possible Power Rangers series that never came to be. But fortunately, CBR can show you several series that never got to make it to the States, so all you diehard Power Rangers fans can impress friends with even more Ranger-related trivia.

15 ZYUOHGER

This one’s a little unfair. The way Saban has worked since they regained the rights to Power Rangers a few years back involves them getting at least two seasons out of every series, the second season usually referred to as the “Super” version. Because of that, this could still be adapted…but with the trend of them skipping seasons to catch up, it’s unlikely.

The Sentai series for 2016-2017, Doubutsu Sentai Zyuohger, or “Animal Squadron Beast King Ranger”, set up quite the deep mythology. To begin with, the show revealed that there was a “hidden” side to Earth known as Zyuland, where all the animals developed into human like creatures known as Zyumans. Both sides normally keep to themselves, but they’re forced to work together when the Earth is attacked by a group of space outlaws known as the Deathgaliens for something they call a Blood Game.

14 DYNAMAN

The earliest series on this list, Dynaman is unique in that the show actually did make it over to the States. It didn’t last long, but a few episodes of the show were aired on USA’s Night Flight block as well as Nickelodeon’s Special Delivery in a dubbed over parody in the late '80s, beating Power Rangers to the punch by five years.

Scientific Squadron Dynaman followed a team of scientists and inventors working under Doctor Kyutaro Yumeno for his invention lab. Dr. Yumeno grants them the powers to become Dynaman just in time to battle against the Jashinka Empire, a race of reptile aliens that arrived on Earth millennia ago and eventually evolved to become scientifically more advanced than humans. After trying and failing to transform humankind into their own, Jashinka simply decided to destroy mankind, with only the Dynaman standing in their way.

13 BIOMAN

Centuries ago, an android known as Peebo and a giant robot traveled to Earth from a place called the Bio Star, with the giant robot (Bio Robo) showered five people with Bio Particles that were passed down through generations. When the monstrous robotic Empire Gear and its leader Doctor Man (…yes, seriously) threaten Earth, Peebo has to find the descendants holding the Bio Particles and assemble them into the heroes of the Super Electronic Bioman.

Bioman was wildly popular in Japan, but it’s also easily got one of the darkest moments in Super Sentai history. When the show’s Yellow Ranger became especially hard to deal with, Toei released her. Unfortunately, that meant they had to find a way to write her out of the picture -- this led to her character being killed off early in the season, only to be replaced with another Yellow Ranger shortly afterwards.

12 CHANGEMAN

Though there’s some dissonance involved when combining the two, the idea of the military and Power Rangers kind of goes hand in hand. After all, they both require teams working together, they both require massive amounts of weaponry, and they’re usually fighting some threat to everything you know and love.

So in 1984, Toei would premiere Blitzkrieg Squadron Changeman, with a series of military members imbued with the power of mythological beasts by an “Earth Force” after being attacked by an imperialist alien force known as the Gozma. With the powers granted by the Earth Force and weaponry directly from the military, they became Earth’s last, best hope after the Gozma wiped out most of the rest of the military in their opening attack. Changeman was wildly successful, and the military theme would be re-used roughly a decade later with 1995’s Ohranger (Power Rangers Zeo).

11 FLASHMAN

Flashman might be one of the most creative seasons of Sentai to emerge from the '80s. In 1966, a group of children are kidnapped by alien hunters. Meant to be human samples to be experimented on by the Reconstructive Experiment Empire Mess, they were all rescued by members of the Flash alien race, then each taken to a separate planet. While there, they all train and learn different superpowers in order to fight back against Mess.

Twenty years later, they return to Earth to stop the alien empire from conquering Earth…and try to find their parents. Unfortunately, after spending so much time adapting to new worlds, the team eventually learns they can only remain on Earth for a single year before the environment becomes toxic to them.

10 MASKMAN

The longer anyone follows Power Rangers or its Japanese counterpart, the more noticeable the theme repetition becomes. For instance, dinosaurs and ninja have been done three times since their use back in the early '90s. Martial arts is similarly popular, between 1993’s Dairanger (MMPR) and 2007’s Gekiranger (Jungle Fury). But the first time they used martial arts was in 1987’s Light Squadron Maskman.

The show was a departure in multiple ways: it’s the first time the series pulled away from its roots as a science fiction show -- their powers came from their own incredible ki, called “Aura Power”. It also featured the first “extra ranger”, though he was only in one episode. But what really makes Maskman stand out are its star-crossed lovers: the Red Ranger Takeru and princess of the evil Underworld Empire Tube fall in love, leading to the villains kidnapping her and encasing her in ice!

9 LIVEMAN

The very first (of so, so many) animal-based Sentai season, Super Beast Squadron Liveman hit airwaves from 1988-1989. Initially set on Academia Island, a school for scientists, Liveman’s story begins when three of the island’s best students abandon Academia to join up with the evil group Volt in order to reach their full potential. This defection runs against the wishes of their best friends Yusuke, Joh, and Megumi, who feel betrayed by their three friends who join Volt and eventually go on to become the Liveman team.

The entire series revolves around this betrayal, as the heroes’ friends rise high in the ranks of the Volt organization, turning them into bitter enemies as the show continues. This is the first series to embrace a permanent addition of Rangers too, as Black Bison and Green Sai turn the three-member team into a squadron of five around episode 30.

8 TURBORANGER

No, your eyes aren’t fooling you -- Japan did a series called Turboranger roughly ten years before America got to it. Moreover, would you believe that Japan gathered five teenagers (though maybe not with attitudes, they were mostly well-mannered) three years before Mighty Morphin’ Power Rangers ever even existed? Though Sentai had been on the air for thirteen years already, typically the team was usually older people in their twenties and thirties.

Still, by the late '80s Toei finally decided to change it up by using a bunch of high school kids as the heroes. They fought against the Boma Tribes, an evil force that was sealed away millennia ago by the humans and a now nearly-extinct fairy race. But after 20,000 years, man’s pollution weakens the seal enough to unleash them again. And no, irony of this being a car-based show yet having an environmental angle doesn’t escape us.

7 FIVEMAN

Earth Squadron Fiveman followed the Hoshikawa siblings, five children that were the sons and daughters of a scientist on an alien world who was attempting to transform it into a lush paradise. Just as their father succeeded, the planet was attacked by the Zone Empire and the Hoshikawa children were sent to Earth by their mother and father. Raised by the family robot Arthur G6, the children all grow up to become teachers working at the same school. Eventually, the Zone Empire chooses Earth as their one thousandth target, but brothers and sisters of the Hoshikawa family have been waiting, having trained and developed special technology just to fight them.

Fiveman is unique for being the first all-sibling team ever created, though they aren’t the last -- 1999’s GoGoV (Power Rangers Lightspeed Rescue) and 2005’s Magiranger (Power Rangers Mystic Force) would revive the idea for their own stories.

6 JETMAN

Birdman Squadron Jetman is one of the more popular older Sentai. When a group of scientists in a peacekeeping agency known as “Sky Force” discovers “Birdonic Waves”, a technology that can grant superpowers, the agency chooses five elite agents to use this new power. They successfully transform one, Red Hawk/Ryu Tendo. The other waves randomly hit other humans in Japan when the agency is attacked by the evil Vyram, an evil group from another dimension.

Their sudden attack on Earth forces Ryu to gather the other men and women and whip them into shape, becoming the bird-inspired team Jetman. The thing most Jetman fans remember the series for though is its iconic, dark ending: the show’s Black Ranger is murdered after stopping a mugging on his way to see the Red and Pink Ranger get married!

5 DAIRANGER

Just as the first season of Power Rangers was on a roll, Saban ran into a problem: they had run out of the footage they were adapting from Power Rangers’ source material series, Zyuranger. They’d done their best to extend it, but eventually they were forced to change things up a bit. They introduced the mecha from this series into the second season of Power Rangers, and changed Tommy from the Green into the White Ranger.

This is a large part of why Tommy looked so much more powerful than the rest of the team. Tommy’s new suit was pulled directly from Dairanger, leaving him to often fight monsters solo while the rest of the team had to work together. The second series based entirely around the theme of martial arts, it’s a shame this series couldn’t be properly adapted for the West.

4 KAKURANGER

This season’s going to look familiar to a lot of diehard fans. With Power Rangers hitting its third season, Saban was again forced to change things up after running out of Dairanger footage. But the company was still unwilling to ditch the popular Power Ranger costumes, so they simply changed the mecha to match the 1994-1995 series Ninja Sentai Kakuranger.

As for the outfits, they split the series’ two different outfits in half. They gave the ninjutsu suits to the regular team, while giving the actual Kakuranger suits to the Alien Rangers from Aquitar. This would be the last season Saban would try and keep the original MMPR outfits, as the Rangers would switch over to Zeo power with the following season, and they’ve been (mostly) changing up every year.

3 AKIBARANGER

Ever wanted to see a Power Rangers series that maintained the franchise’s heroic, idealistic feel but felt a little more aimed at adults? Unofficial Squadron Akibaranger turned out to be exactly that. The story followed the adventures of Nobuo, Mitsuki, and Yumeri -- three members of a Super Sentai super fanclub living in the mecca for geeks, the city of Akihabara. There, they wage a war against the Delusion Empire, an evil mega-corporation that seeks to turn Akihabara away from its geeky ways.

Set in the “real” world, their fights are supposed to be occurring only in their overactive imaginations…but when it’s revealed it isn’t the group gets their chance to become a “true” Sentai team. Filled with tons of in-jokes and Easter eggs for Sentai and Power Rangers alike, Akibaranger is the perfect celebration of the franchise that doesn’t become needlessly self-indulgent.

2 GO-BUSTERS

Special Operations Squadron Go-Busters was Sentai’s 2012-2013 season. Set in a city with futuristic technology (that was still somehow present day), the entire city ran off a new energy source known as Enetron. Enetron was so powerful that a group from a different dimension known as the Vaglass sought to steal it, and the only thing standing in their way were a group of young heroes working for the Energy Management Center, the Go-Busters.

Meant to be a team of super-spies, this show is filled with overt references to Power Rangers itself. The Go-Busters transformation device utters the phrase “It’s Morphin’ Time“ before they transform, and both the good and evil robots in the series are literally referred to as MegaZords. Still, the series was passed over in favor of adapting the series after it, Kyoryuger, into the series Power Rangers Dino Charge.

1 TOQGER

Another of the rare series coming after Mighty Morphin’ Power Rangers started that avoided being adapted into an American series. ToQger, or Train Squadron Limited Express Ranger, followed a group of childhood friends who maintained enough of their imagination to see the Rainbow Line, a mystical railway running giant trains called Ressha. These friends use their powers to battle Emperor Z and his Shadow Line, a group seeking to permanently plunge the world into darkness by taking advantage of the fair and sadness they spread.

Though this series popular in Japan, a large part of that was due to its train theme. In Japan, the railways serve as a central means of transportation, so they’re naturally more popular than they are in the West. Presumably because of that, Saban skipped adapting this show in favor of making the currently airing Power Rangers Ninja Steel. Because ninja are cooler than trains.