Deciding to take advantage of Earth's problems, an evil band of aliens called the Space Mafia decide to invade in the mid 1990s. To defeat them, a special covert anti-alien police unit called Blue SWAT is established by the Japanese government. One day, the Mafia attacks the Blue SWAT's base and kills them all. Everyone, that is, except three brave heroes. The heroes set up shop on their own and with the help of their allies, dedicate themselves to defeat the Space Mafia.
- Shou Narumi/Agent #153, Blue armor: The Hero, very much Hot-Blooded. He later gains a Super Mode called Hyper Shou.
- Sara Misugi/Agent #071, Purple armor: The Lancer; a By-the-Book Cop who's also the lone female.
- Sig/Agent #011, Grey armor: The Smart Guy. Revealed to be an Alien Among Us early on.
The Space Mafia:
- Jisp: The Dragon-in-Chief
- Riga, Zodor and Yanimi: Jisps minions, who serve as recurring bosses.
- Madamoiselle Q/Queen: The Man Behind the Man.
Blue SWAT provides examples of the following tropes:
- Alien Blood: Sig's blood is green.
- Body Snatcher: The Space Mafia's modus operandi. Referred to as "Invasion" (in Engrish) in-universe, and is a standard ability amongst Aliens. Staying in one body for too long makes the takeover permanent (as Sig finds out), and if the host is mentally strong enough he/she can exert some influence over their Invaded body.
- Code Name: Averted. The three survivors don't have code names, likely because the size of Blue Swat would have made it difficult. They instead use their given names.
- Cool Guns: The BW-01 Dictator is a Beretta M9 with kibble attached to it. Normal magazine is 10 rounds, comes with an optional 32-round Long Clip, and fires titanium-coated artificial ruby AP rounds that the gun itself then further gives an energy coating. It is powerful and accurate.
- Cop Show: The Toku version!
- Darker and Edgier: While it maintains the surrealism of the other series, the more "down-to-earth" tone of the show makes it a more serious and grittier entry than others.
- Everybody's Dead, Dave: Our heroes are the last ones left out of their organization after the others were all killed very, very suddenly in the first episode.
- Glass Cannon: For being Metal Heroes, the standard Blue Swat armor is a protective vest and a helmet collectively called the "Protect Gear". The rest of their body is covered in spandex, apparently — in-universe! They make up for it by having really heavy firepower at their disposal. The flip side is that they aren't encumbered with heavy armor, and can move around very quietly.
- Gun Porn: They were very serious about their standard firearm early on, but this was toned down later (probably due to the extra work required to keep model guns in operative condition).
- Hand Cannon: The BW-01 Dictator. It says something when the all-round most effective weapon available to Blue Swat is their handgun, and they've got access to a missile launcher.
- Human Popsicle: When Sig, desperate for a way to move around on Earth without suspicion, took over his current body, he made sure it was that of a brain-dead man frozen for organ donation reasons.
- Lighter and Softer: Suddenly turned to this around midway through, for different reasons than Chouriki Sentai Ohranger. Apparently, it was having trouble attracting the targeted child audience (but was doing fine with older fans).
- Masquerade: The public at large isn't aware that either Aliens or Blue SWAT exist, and both sides work to keep it that way. The Space Mafia does so because they're severely outnumbered, while Blue SWAT does so for more mundane reasons.
- Monster of the Week: Sometimes they work for the Space Mafia, sometimes they are completely independent of the plans.
- Named Weapons: While it's really standard convention for guns to have names, Blue Swat's standard sidearm is the BW-01 Dictator.
- Really 700 Years Old: 800, actually — although it's unclear if the human body Sig is inhabiting will be as long-lived as he is.
- Soundtrack Dissonance: The opening theme and ending songs seems way too upbeat for this type of show.
- This Is Unforgivable!: This is how Shou enters his Super Mode.
- Who You Gonna Call?: The Blue SWAT unit — that is before they were wiped out in the first episode.