Commander Sugata discovered the existence of the Royal Underground Empire Tube, a malignant force that desires to dominate the land, which is based underneath Japan. He recruits five young people, each one specializing in a style of martial arts, and teaches them in the ways of the mystical "Aura Power" energy. A year after he recruited and trained the Maskmen, Tube is ready to strike.
Episode 1
Five youths begin their battle against the underground forces of Tube as Maskman after they begin a war with the surface with the abduction of the mysterious Mio.
Episode 2
Takeru abandons Commander Sugata's Aura Power training when he receives a message from Mio about her survival and current whereabouts as Tube prepares to punish her.
Episode 3
As Emperor Zeba plunges the world into eternal darkness, the Maskman must complete their Aura Power training, even as Prince Igum decides to face Takeru for the shame Mio has brought him.
Episode 4
The Maskman must save a boy and his father trapped within a tunnel transformed by Oyoboo into an endless Medius tunnel.
Episode 5
Akira's teammates become frustrated with his childish behavior, and he tries to prove himself as Skull Doggler and Fumin start swapping people's faces.
Episode 6
While investigating a series of unusual earthquakes in Otaki, Takeru meets a boy who believes he possesses a legendary martial arts move.
Episode 7
Kenta encounters a girl who likes him, inspiring Baraba to use a Doggler to sabotage his new love.
Episode 8
Igum uses a special flower to lure out Akira and Momoko to save their teammates after the other Maskman become frozen by a Doggler.
Episode 9
Takeru unexpectedly summons an alien child to Earth with his Aura, which interferes with Baraba's scheme to cut off the planet's electricity.
Episode 10
Igum challenges Takeru to his family's ceremonial Death Ring match, a cage showdown where only one of them will leave the battle alive!
Episode 11
Kenta pursues a former ninja from underground who has abducted a crown associated with the truth behind Emperor Zeba.
Episode 12
Haruka is forced to join in a showdown between Fumin and Oyoboo to defeat a ninja Doggler that can grant the ultimate shinobi power
Episode 13
Kenta investigates an idol with a reporter when he discovers she may be part of a plot to create a stronger army of Ungler Soldiers for Tube.
Episode 14
Akira is dragged underground into a city where he meets children of Tube's empire who only dream of the surface and the sky.
Episode 15
A flower cared for by Momoko becomes the key to stopping a Doggler's deadly flower that kills as it sprouts.
Episode 16
Kenta must fight alone against Baraba after the Tube general steals the Aura from his teammates to strengthen his powers.
Episode 17
Takeru is lured by Igum into a building transformed into a maze by a Doggler to confuse and wear him down.
Episode 18
Haruka gives a doll she formerly owned to a girl who desires it, unknowing of the Doggler hiding within threatening to kill her.
Episode 19
Anagmas uses his magic to enhance the Tube forces while making Akira lose his memories during a sneak attack.
Episode 20
Momoko's pride as a kenpo teacher is tested by a powerful opponent set up by Anagmas as part of a scheme to defeat Maskman and Great Five.
Episode 21
With Great Five buried underground, Sugata decides to investigate a rival mecha that has gained infamy for killing its creator.
Episode 22
With Galaxy Robo in their hands, the Maskman head forth to save Great Five, unknowing of the difficulties of doing so and an unknown key to fully activate their new mecha.
Episode 23
A Doggler transforms a woman into a fake, evil Mio to lure Takeru into a Tube trap.
Episode 24
The Maskman are summoned to Inasa where a boy is mutated into a monster by a Doggler as a city friend comes to visit.
Episode 25
Akira enters a martial arts tournament unknowingly controlled by Tube due to a letter he has received from an unexpected writer.
Episode 26
Kenta encounters a sorrowful girl who is actually a creature working to empower a Doggler while trying to preserve her own short life.
Episode 27
Thief Knight Kiros, a lone wolf of the underground, takes on the Maskman in hopes of defeating them and winning Princess Iaul for himself.
Episode 28
An assault by Kiros draws Takeru away from research for Shot Bomber's replacement, where he finds out the truth about Mio and her current fate.
Episode 29
The Maskman rush to face a Doggler while their new cannon remains incomplete against the warnings of their head engineer, who has personal ties with their enemy.
Episode 30
Akira decides to help Baraba's mother reach her son when he decides to partake in a trial to gain the legendary sword of the underground.
Episode 31
Igum attempts to gain the assistance of his family's guardian to increase his power, while Haruka has a crisis in the sudden loss of her own abilities.
Episode 32
Kenta discovers a derelict car of a racing friend he decides to use to cheer him up, even while being chased by Oyoboo for accidentally obtaining a part of Baraba's latest plot.
Episode 33
Takeru encounters an underground girl who wants to help him even though she has sworn her love to Kiros.
Episode 34
A Doggler takes a human form in order to pursue love with Momoko, under the condition he destroys the Maskman in three days!
Episode 35
Kiros opens a sealed tomb revealing a powerful Doggler that may be associated with Zeba's greatest secret.
Episode 36
Igum uses a Doggler to turn twin sisters into a combined menace as they destroy while trying to reunite with one another.
Episode 37
Kiros uses a Doggler to remove Kenta's courage, forcing a boy he protected to help him rediscover his dreams to regain it.
Episode 38
Igum devises a plan to go back in time and kill Takeru when he's little, thereby creating a time paradox. The Maskman must stop this plan, while getting to see how Takeru is like when he is a kid.
Episode 39
When a sixth Maskman saves the team from an attack, Takeru investigates to find out why he vanished from their battle with Tube.
Episode 40
A famous pianist returning to Japan is suddenly targeted by Tube due to a unknown connection with them and her mysterious benefactor.
Episode 41
Kiros uses a Doggler to transform Haruka and Momoko into evil female thieves stealing wealth to give to Iaul.
Episode 42
A cowardly boy gains super-strength to defend himself after eating a cave mushroom Baraba wished to harvest for himself.
Episode 43
During a revenge attack by Kiros for stopping his previous research, Akira begins to hear a strange chant from underground that makes his eyes go blind.
Episode 44
The underground refugees complete a ritual in an attempt to awaken a great hero, but instead awaken a Doggler of the Igum clan who rewards its power to a surprising warrior...
Episode 45
The Maskman discover the truth behind why Akira was transformed into the Underground Knight Unas as they fight to get him back from Igum's control.
Episode 46
Igum's teacher guides her to a pond where Lethal Doggler was born to gain its power, only to learn a surprising revelation regarding what lies within.
Episode 47
A dance student of Haruka is abducted to take part in Tube's ceremony to summon victory in their final war on the surface.
Episode 48
With no more chances left in Tube, Baraba joins with Kiros to abduct the frozen Iaul in a final chance to defeat Takeru.
Episode 49
With Kiros possessing Iaul's frozen body, Takeru and Igum both try to get her back in order to control her ultimate fate before the thief knight can thaw her out.
Episode 50
Iaul and the Maskman obtain a ball that reveals the truth behind Emperor Zeba, even as he begins his final plan to raise the Underground Castle and cover the world in darkness.
Episode 51
As Zeba finally unleashes eternal darkness upon the world, the Maskman must work with the twins of the Igum royal family and complete the restoration of light upon two realms.
