Debo Nagareboshi is a vain yet very powerful Debo Monster of the Zetsumates group. He is themed after a meteoroid, specifically the Chicxulub impactor that caused the extinction of the dinosaurs, and is armed with the Meteor Shields and the Star-Whizzing Machine, which supercharges his meteor attack.
Using the meteorites on his waist, he can perform the Meteorite Balls normally, the Great Galaxy Balls after being enhanced with Deboss and Chaos' energy, and the Super Galaxy Balls attacks after acquiring the Star-Whizzing Machine.
Nagareboshi was sealed away within a volcano before being awakened by the power boost caused by Deboss's stirring, then traveled all the way to Japan to give the Kyoryugers a solid thrashing. It was only thanks to a resolved Kyoryu Gold's Lighting Shockwave nicking a part of his body that Nagareboshi ran off to polish his body.
After learning of the deaths of his fellow Zetsumates, Debo Hyogakki and Debo Viruson, Debo Nagareboshi vowed to avenge his fallen comrades, and decided to do that with the help of Dogold. As they started to tear up the city to look for the Kyoryugers, the Kyoryugers have found them, now stronger then their previous encounter, thanks to Kyoryu Gray's training. And it was thanks to said training that the Kyoryugers managed to badly beat up Nagareboshi, until it was Kyoryu Red's turn up to fight Nagareboshi. Unlike the others, who found a way to boost their power with Brave energy, Kyoryu Red didn't get stronger from Kyoryu Gray's training, and it was this lack of development that had spared Nagareboshi and allowed him to flee, though not before Kyoryu Gold to smash Nagareboshi's left Meteor Shield with a thrust of the Kentrospiker after Kyoryu Red failed to even nick the Debo Monster with the weapon.
At the Frozen Castle, a boosted Chaos repairs the nick Nagareboshi had on his chest, as well as replaced the destroyed Meteor Shield on his arm with the Star-Whizzing Machine. With his new improvements, Nagareboshi went off and started causing mayhem. When Kyoryu Gold ran to fight Nagareboshi, the improved Debo Monster overwhelmed the Kyoryuger with the newest variant of his signature technique, then took him hostage as so Dogold could try and make Utsusemimaru mad enough to possess him again. However, that backfired when Utsusemimaru didn't give into his rage, and Dogold decided to end the Thunder Hero's life, which rewarded him getting flying side kicked by Daigo, sending him into the stunned Nagareboshi.
With the Kyoryugers regrouped, they charged forward and attacked the Deboss offense. Cursing Kyoryu Red, he unleashes the same technique that defeated Kyoryu Gold, but the Red Kyoryuger destroyed them all with his new-found strength and his Gabutyra Fang. Desperate, the ancient Debo Monster used the Star-Whizzing Machine to unleash his newest and most devastating move, and like his last move, Kyoryu Red blasted his way through the attack and destroyed the Star-Whizzing Machine with his signature move. He is then soon finished off by the Kentrospiker, the Debo Monster losing his last Meteor Shield in the process to block the javelin in vain.
Once enlarged, Nagareboshi wordlessly summoned a hailstorm of meteors from the heavens, striking Kyoryuzin Macho relentlessly. The tide turned back into the favor of the Kyoryugers when Kyoryu Gray entrusted the team with Zyudenryu Bunpachy, whose hard-hitting meteor hammer distracted Debo Nagareboshi long enough for the Kyoryugers to form Kyoryuzin Kung Fu. The Biting Combination overwhelmed Nagareboshi with hard-hitting fast strikes, knocked him down with a Furious Breakthrough, and ended the Debo Monster with a Kyoryuzin Kung Fu Brave Finish.
Debo Nagareboshi is later resurrected, along with fellow Zetsumates members Debo Hyogakki and Debo Viruson, from the dead when Chaos senses Plezuon and Kyoryu Violet returning to the planet, urging his Knights to join their powers together. As the Zyudenryu entered the exosphere, Plezuon was hit by Nagareboshi's Super Galaxy Ball attack, knocking the Zyudenryu's flight path crooked and sent it careening into the sea. As the Kyoryugers that had arrived to the shore overlooking the stretch of sea that Plezuon crashed into, the Zetsumates attacked then reintroduced themselves in a style similar to the Showa-Era Sentai Rangers, but when the Kyoryugers tried to introduce themselves, Nagareboshi used his Super Galaxy Ball attack to blow the Kyoryugers away. As the stunned Kyoryugers tried to get back up, the Zetsumates charged at them, with Nagareboshi fighting Kyoryu Red and Gold.
Kyoryu Black then grappled with Nagareboshi, telling Kyoryu Red to go find out if Plezuon and Violet were alright, but as soon as the Fanged Hero left, the Zetsumates unleashed their newest technique, the Deboss MetsuBall, on the Kyoryugers, flooring them from the shockwaves of the explosion it created.
Enlarged, Nagareboshi was soon destroyed by Rocket Henkei PlezuOh
- Height: 209 cm (50.5m: giant)
- Weight: 170 kg (425.0t: giant)
- Debo Nagareboshi's name derives from the characters that make up "meteor", with the first character being pronounced in the Kun'yomi method.
- Debo Nagareboshi is the first Debo Monster to last for more than one episode.