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Shows Like Gate Keepers 21

For those captivated by Gate Keepers 21, should consider this hand-picked list which questions the purpose and weight of our choices while grounding the story in targets the intellect with complex, multi-layered ideas. Carefully balances character depth with narrative flow makes this definitely worth a watch.

Mood Breakdown
Runtime Cluster

Standard feature-length experiences.

Viewer Fit

Best for fans of who appreciate concise storytelling.

Top Picks

Birdy the Mighty: Decode
7.1

Birdy the Mighty: Decode

2008

While pursuing fugitives the Space Federation police officer Birdy Cephon Altera finds herself on Earth.

Lilo & Stitch: The Series
7.4

Lilo & Stitch: The Series

2003

This animated series chronicles the further adventures of renegade scientist Dr. Jumba Jookiba's beloved Experiment 626, who is now living happily as Lilo's alien buddy Stitch. Jumba’s remaining experiments have landed all over Hawaii in the form of dehydrated pods. Lilo and Stitch’s mission is to catch Stitch’s "cousins" before they fall into the clutches of the evil Dr. Jacques von Hamsterviel!

Aquarion
6.5

Aquarion

2005

Set in the future, a giant fighting machine called the Aquarion is humanity's only effective weapon in the fight against the technologically advanced species called the Shadow Angels.

Captain Planet and the Planeteers
6.8

Captain Planet and the Planeteers

1990

Eco-villains beware: Captain Planet is here to save the day! With the guidance of Gaia, five Planeteers - representing Earth, Fire, Water, Wind and Heart - come together to defend our planet from environmental destruction. With their powers combined, the team becomes the solution to pollution!

Sgt. Frog
6.9

Sgt. Frog

2004

Alien frogs come to take over the planet & get into all kinds of trouble while living under the roof of a small family.

Justice League Unlimited
8.3

Justice League Unlimited

2004

The galaxy's most powerful superheroes return to battle the allied villains and criminal plots that endanger the universe.

Ben 10
8.2

Ben 10

2005

When 10-year-old Ben Tennyson discovers a mysterious device, he gains the power to change into ten different alien heroes, each with uniquely awesome powers. With such abilities at his disposal, Ben realizes a greater responsibility to help others and stop evildoers, but that doesn't mean he's above a little superpowered mischief now and then.

Farzar
6.0

Farzar

2022

Follow the adventures of Prince Fichael and his crew as they venture out of their domed human city to fight the evil aliens that want to kill and/or eat them.

More Shows Like Gate Keepers 21

The Invaders
6.8

The Invaders

1967

The Invaders, alien beings from a dying planet. Their destination: the Earth. Their purpose: to make it their world. David Vincent has seen them, for him it began one lost night on a lonely country road, looking for a shortcut that he never found. It began with a closed deserted diner, and a man too long without sleep to continue his journey. It began with the landing of a craft from another galaxy. Now, David Vincent knows that the Invaders are here, that they have taken human form. Somehow he must convince a disbelieving world that the nightmare has already begun.

Saber Rider and the Star Sheriffs
8.1

Saber Rider and the Star Sheriffs

1987

In the distant future, humanity has colonized the stars. To maintain peace and order across mankind's New Frontier, Earth's Cavalry Command develops the "Ramrod Equalizer Unit", a transforming battleship operated by their elite unit of special operatives, the Star Sheriffs, to defend the settlers of the galaxy. Their biggest threat? The Outriders, a group of extra-dimensional beings that intend to conquer our dimension and enslave humanity with their superior technology and weaponry. Armed with their wits, courage, and of course, Ramrod, it's up to Saber Rider and his team to stop the Outriders once and for all and bring peace to the universe!

Star Wars: Clone Wars
7.8

Star Wars: Clone Wars

2003

During the Clone Wars, Jedi Master Obi-Wan Kenobi leads an assault on the planet Muunilinst, home of the Intergalactic Banking Clan; and his Padawan, Anakin Skywalker, is appointed by Supreme Chancellor Palpatine to lead the Republic’s space forces. Meanwhile, Separatist leader and Sith Lord Count Dooku takes in Force-sensitive gladiator Asajj Ventress as his Sith apprentice, and tasks her with eliminating Skywalker.

Batman: The Brave and the Bold
7.6

Batman: The Brave and the Bold

2008

The Caped Crusader is teamed up with Blue Beetle, Green Arrow, Aquaman and countless others in his quest to uphold justice.

The Wonderful Adventures of Nils
7.7

The Wonderful Adventures of Nils

1980

Nils Holgersson is a young boy on a farm who is cruel to the animals. But when he catches the farm's little goblin it becomes one prank too many. He is magically shrunk and suddenly the farm animals are out for revenge. He flees on the back of the goose Morten and they join up with a flock of wild geese. Together they travel all over Sweden, with Nils hoping to find a way to become big again.

Space Pirate Captain Harlock
7.2

Space Pirate Captain Harlock

1978

When a mysterious invader from the stars catches Earth unawares, only the legendary space pirate Captain Harlock and the crew of the Arcadia have the will to stand against them.

Captain Scarlet and the Mysterons
7.4

Captain Scarlet and the Mysterons

1967

Captain Scarlet and the Mysterons, often referred to as Captain Scarlet, is a 1960s British science-fiction television series produced by the Century 21 Productions company of Gerry and Sylvia Anderson, John Read and Reg Hill. First broadcast on ATV Midlands from September 1967 to May 1968, it has since been transmitted in more than 40 other countries, including the United States, Australia, New Zealand and Japan. Characters are presented as marionette puppets alongside scale model sets and special effects in a filming technique that the Andersons termed "Supermarionation". This technology incorporated solenoid motors as a means of synchronising the puppet's lip movements with pre-recorded dialogue. Set in 2068, Captain Scarlet presents the hostilities between Earth and a race of Martians known as the Mysterons. After human astronauts attack their city on Mars, the vengeful Mysterons declare war on Earth, initiating a series of reprisals that are countered by Spectrum, a worldwide security organisation. Spectrum boasts the extraordinary abilities of its primary agent, Captain Scarlet. During the events of the pilot episode, Scarlet acquires the Mysteron healing power of "retro-metabolism" and is thereafter considered to be virtually "indestructible", being able to recover fully from injuries that would normally be fatal.

Gachiakuta
8.6

Gachiakuta

2025

Accused of murder and thrown into the Pit, a young orphan joins a group of monster fighters with special powers to uncover the truth and seek vengeance.

Monster Farm
8.1

Monster Farm

1999

Genki is a boy who loves playing the Monster Rancher games and one day he's somehow transported into the world of the video game where he meets the girl Holly and the monsters Mochi, Suezo, Golem, Tiger and Hare. Together, they are searching for a way to revive the Phoenix, which is the only monster capable of stopping the evil Moo.

Space Ghost and Dino Boy
7.5

Space Ghost and Dino Boy

1966

Intergalactic policeman Space Ghost navigates the cosmos in his tricked-out spaceship, The Phantom Cruiser, battling villains like Brak and Zorak in his legendary suit and powerful wristbands. Dino Boy teams with caveman Ugh and dinosaur Bronty to go primeval on the ancient menaces of their primitive home.

UFO Robot Grendizer
7.6

UFO Robot Grendizer

1975

The story revolves around Duke Fleed who is a survivor of the Vega Star, raised by Dr. Umon as his adoptive son, and known as Daisuke Umon on Earth. Years after his arrival, he's faced with the threat of King Vega and his army, who want to conquer the Earth. With his friends Koji and Hikaru (and later his kid sister Maria Grace), Duke decides to fight back using his best weapon, the almighty Grendizer.

Green Lantern: The Animated Series
7.7

Green Lantern: The Animated Series

2011

The Green Lanterns Hal and his partner Kilowog fight against the forces of the Red Lanterns.

Why These Shows Are Similar

These recommendations share core qualities with Gate Keepers 21 (2002): Animation and Action & Adventure themes, similar pacing, and comparable production quality. NoBadPicks uses TMDB collaborative filtering, genre matching, and AI analysis to surface series most likely to resonate with fans of Gate Keepers 21.

See full details for Gate Keepers 21 (2002)

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