* AbortedArc: In Episode 43, Akira loses his eyesight but manages to rescue his friends in the nick of time. [[spoiler: But the blindness doesn't get cured right away, leaving Akira open to be possessed by the disembodied armor of Armor Doggler, transforming him into Underground Knight Unas. Commander Sugata remarks that the onlyway he could have even be susceptible is if Akira was from the Underground Empire. Everyone else is in total shock and it looks like a big reveal is coming up]]. This arc lasts two more episodes but is then eclipsed by the reveal of [[spoiler: Prince Igam being a woman]] which sets the track for the homestretch of the series. However, [[spoiler: Akira is turned back to normal, and the question of is true heritage [[TheyWastedAPerfectlyGoodPlot is never brought up again]]]].
* BigLippedAlligatorMoment: The opening credits features a naked body-builder flexing, summoning energy and blasting a big block of ice... which explodes to reveal the five members of the team.
* CompleteMonster: Emperor Zeba. Tube's dictator, who has absolutely no compunction about killing or punishing his subordinates. His monstrosity is finally revealed in the final episodes where it turns out that he is [[spoiler:actually the spawn of Rizal Doggler, a malignant creature who tried to usurp the throne and was defeated by the original Tube royal family. After which he ate his dying father in order to become stronger. Driven by a seething hatred against humans from both sides of the crust, it proceeds to destroy the rest of the original family save Ial and Igam, taking over as emperor and corrupting the peaceful Tube into becoming a militaristic Crapsack World using enslaved underground humans in an attempt to reach the surface world and extend its malicious grip.]]
* CrowningMusicOfAwesome: The opening music is ''[[http://www.youtube.com/watch?v=1_HzzV-ylEw very awesome]]''. Thank you, [[JAMProject Hironobu Kageyama!]]
** What about the ''[[http://www.youtube.com/watch?v=EXIgTpC1IvA ending theme]]''? Again, thank you, [[JAMProject Hironobu Kageyama]].
*** [[http://www.youtube.com/watch?v=MNSghC3yPS8 Even the Filipino version of both themes is epic]].
** So is the movie's [[http://www.youtube.com/watch?v=0JoUTwuLTUw opening]]. [[RuleOfThree Yet again, thank you,]] [[JAMProject Hironobu Kageyama]]!
* FanPreferredCouple: There's a lot of fans who'd rather Takeru end up with Momoko eventually. Also an example of ShipsThatPassInTheNight since Takeru and Momoko don't get a focus episode together or even talk to each other very much.
** Takeru/Haruka is also a popular pair, and might have more support in a way that Haruka was once a recipient of Takeru's GetAHoldOfYourselfMan.
* GermansLoveDavidHasselhoff: One of the inexplicably popular sentai series aired in the Philippines, including a Tagalog dub of the opening/closing themes.
** Also reciprocated because Ryosuke Kaizu (Red Mask himself) migrated to the Philippines and now has a family with his Filipino wife.
* HilariousInHindsight: X-1 Mask's design differs greatly from the existing Maskman design scheme - while he might not pass for one of them, [[Series/BattleFeverJ he'd make a passable Battle Ireland.]]
* TearJerker: Episode 24, where a boy gets transformed into a monster by the MonsterOfTheWeek.
** Also in Episode 26, the one where Kenta meets Seira and dies in the hands of the MonsterOfTheWeek. The sad music did not help.
* TheUntwist: [[spoiler:Prince Igam is actually a woman. Not much of a spoiler, considering "he" was obviously played by a female, with no attempt whatsoever made to disguise the face or voice... and it doesn't help matters much that the title of the episode where this is "revealed" is "Prince Igam, you're a woman!", as though it weren't obvious enough to begin with.]] Really, TheReveal is the first time you realize it was ever intended to be a secret. However, we do learn much more about her that goes on to be quite relevant to the rest of the series.
** To a lesser extent that Takeru's girlfriend is really the princess of Tube, which we find out early in but the Maskmen themselves are ignorant of for most of the show.
** Made fantastically weird in the brazilian dub. Igan is still dubbed by a voice actress, but she does not make any effort to make her voice sound a bit more male. Also, some fans are creeped out by the fact that she also voiced [[Series/ElChavoDelOcho Doņa Florinda]].
* UglyCute: Okelampa
* ValuesDissonance: The male Maskmen jokingly impersonate criminals to get the female members to strip. That strikes a modern viewer as rather creepy.
** Takeru delivering a GetAHoldOfYourselfMan slap to Haruka makes perfect sense in context, though that still doesn't make it any less uncomfortable to watch.