''Ultraman Cosmos'' was created in the wake of the 35th anniversary of Ultraman, and is one of the most controversial series in the entire ''Franchise/{{Ultra|Series}}'' franchise. The series aims for a kinder, gentler Ultra Hero with emphasis on saving the monsters rather then destroying them, and a hero who fights very defensively. Still, here's the story as quoted from the Other Wiki:

"A kinder, gentler Ultra hero was released in the summer of 2001 to coincide with the 35th anniversary of the original ''Ultraman''. The launch of the TV show is quickly followed by a feature film prequel, and is the first time for an ''Ultra'' movie and TV series to be so closely linked. Following recent trends, Cosmos is another type-changing Ultraman, with the all-blue Luna and asymmetrical red and blue Corona modes. The modes represent a "gentle" side and a "strong" side, respectively. Later in the series, Cosmos also develops the "courageous" Eclipse mode, with a symmetrical blue, red, and gold design. The series was extended to 65 episodes, which makes it the longest-running in the franchise to date.

This series is preceded by the feature film ''Ultraman Cosmos: The First Contact''. The TV series takes place eight years after the events in the movie, when monsters are once again plaguing humanity. Now Musashi is a 19-year-old young man. He joins a wing of SRC known as Team EYES. Musashi encounters Cosmos again, and the two merge to defend the Earth.

The recurring villain in this series is the Chaos Header, a virus that either infects monsters or replicates them, creating a more violent and aggressive version."

This series is also notable as being the longest TV series of the franchise, with 65 episodes, and three movies. Again the series is very LighterAndSofter and can be very polarizing; still most Ultrafans agree the movies are awesome.

!!''Ultraman Cosmos'' provides examples of the following tropes:

* AlternateUniverse: From the Showa-verse, Tiga/Dyna-verse, and Gaia-verse.
* AntiVillain: Believe it or not, the Baltan in the first movie.
* BigBad: Chaos
* GondorCallsForAid: The bonus of living in a universe where many Kaiju and aliens are decent beings is that they would occasionally come to Cosmos's rescue if needed.
* EldritchAbomination: Chaos Header.
* HeelFaceTurn:
** Many of the monsters do this, due to Cosmos preferring to pacify or purify them instead of killing them.
** [[spoiler:Chaos Header ultimately does so in the end, transforming into an angelic being and leaving the planet willingly upon being purified and having a HeelRealization. We find out in a follow up that it becomes the guardian of a planet acting as the sanctuary for benevolent or benign monsters.]]
* LighterAndSofter: One of the lightest entries in the franchise.
* LovecraftLite: Chaos Header.
* MultiformBalance: Interestingly, at first this is less 'this form is strong and this one isn't' and more 'combat mode and pacify mode.' Luna form has no FinishingMove and largely is devoted to pacifying and purifying it's opponents while Corona mode is more combat based and actually capable of using lethal force. [[SuperMode Eclipse Mode]] is a combination of both and has the ability to do either, and it's FinishingMove can purify good monsters and destroy evil ones (sometimes at the same time).
* RousseauWasRight: Many of the Kaiju and aliens, if not the humans, are decent beings in essence. [[spoiler:This includes Chaos Header.]]
* SpaceWhale: The [[spoiler:Fake]] Space Whale Jirak, who is gentle as can be. Then [[TheVirus Chaos Header does what it usually does]].
* TechnicalPacifist: Cosmos, to the point where his default Luna Mode has no finishing attacks at all. He will only switch to his more powerful Corona Mode when there is absolutely no other option or when he's facing something that's completely evil.
* TheVirus: Chaos Header.
* TurnsRed: Cosmos changes color from blue and silver to red and silver with blue patches when transforming into his Corona Mode. This is justified further by the fact that Cosmos usually changes into Corona Mode once he has suffered at least some injury.