Keroro is just as dangerously competent as his reputation states.But he has to have some actual motivation to use it. Keroro likes the place he's in on earth and the friends he's made, he sees no reason to actually go and conquer earth seriously and even makes a game out of creating the most ridiculous invasion schemes. Natsumi's abuse of Keroro actually doesn't harm him very much(if at all) and pretends to fear her so that she feels in command-thus giving her no reason to try and get rid of him. The other platoon members may notice this but all have their own reasons for not wanting to complete the invasion. Tamama-He lives in a mansion and has access to all the snacks he could ever want, also is best friends with Momoka. Giroro-His crush on Natsumi. Dororo-He doesn't really care about invading in the first place. Kururu-Doubt that Kururu cares about the invasion either...
Keronians' sex organs are on their heads.In one episode Giroro is grossed out by the mere suggestion of Keroro taking his hat off. They don't wear any other clothes, why would they only wear hats and consider it taboo to take them off?
Koyuki is an orphan and not a ninja.We don't see her parents, and despite living in a "secluded village", we never see other ninjas. Koyuki actually seems to live on her own, since she has no problems with Dororo making unannounced appearances, and she became obsessed with ninja as a coping mechanism for the apparent absence of a family. Dororo is likewise interested in her hobby, but particularly understands the feeling of being left out and forgotten.
Tamama's growth is stunted by high blood sugar and his jealousy.Thinking about it, it makes sense that the two would be related. There are people have had their growth stunted by drugs, alcohol and even being angry all the time so it's possible that Tamama's candy addiction is the reason why he hasn't fully matured yet. To prove my point, if you look at the crowd that Tamama is standing with during the Kero Zero short you'll notice 1-that a lot of his supposed age mates look older than him and 2-that he's just as addicted to candy on Keron as he is on Earth.
Fuyuki and the Keroro platoon may be a Reconstuction of Dib, Zim and Gir from Invader Zim, with the other cast as other charactersIf this holds true, then:
Keroro is a faulty clone of the original Keroro.The Keroro we know and love from the manga/anime is actually a clone. Either the original Keroro met an unfortunate accident, or 'Keroro' was meant to replace his famous, revered father. But something went awry with the process, and Keron Force dispatched him to Earth without realizing that he was flawed.
Keroro and company arn't products of Shinji hillucinating, rather it's the OTHER WAY AROUND!
Obligatory Evangelion TheoryYou know the drill: Shinji hillucinated the whole thing, blah blah blah, intrumentality.
Starfruits originated from Keron and have become extinct there.They were brought over by an invasion force prior to the Sergeant's and eventually adopted by Pekoponians. Back on Keron, a parasite wiped them out. This explains why (as Kururu noted) it was "strangely high in Keronian planet essence". There are no records of starfruit left on Keron because they have been rendered extinct for a long time, and it's high in Keronian planet essence because it's from Keron.
Giroro's cat is secretly an alien invader.She's trying to soften up the platoon (or at least Giroro) in order to divert their attention from their invasion of Earth so as to allow her comrades to take Earth without trouble from them.
Joriri is Keroro's real father.Come on, they're both rather dim and silly, and green, and they have the same eyes. Joriri is far more like Keroro than the Demon Sergeant. Not to mention they've always been close, to the point were Joriri now lives somewhere in the Keroro Platoon's base. A father secretly looking after his child? Hmmm...
Keroro's friendship with Fuyuki is partly a 'do-over' for his friendship with Zeroro.Several parallels can be drawn between Fuyuki and Zeroro. Both are (or were) soft-spoken young men with Shrinking Violet tendencies. Both have few friends at school, and are delighted to have Keroro for a best friend, despite all the trouble that friendship leads them into. Keroro, naturally, takes full advantage of that. Both are slow to anger, but terrifying when they finally snap. As dense as Keroro can get, he has picked up on the similarities, even if only subconsciously. He also got to see how Zeroro turned out, and has been shown to regret it (even gaining a 'Guilt Switch' in the anime). But this time around, he can do it right. ...Not that he's actually all that good at maintaining that resolve. But Fuyuki does sometimes function as a sort of Morality Pet for him at times, and he does appear to put more effort into actually acting as his friend instead of just using their friendship for his own ends.
The Keroro Platoon was never expected to actually invade because, unknown to them, they're just there to make a profit-grossing TV show for a company on Keron.While the Keroro Platoon is fully aware that their antics are being aired on Keron television, they still think it's an 'update on the invasion' sort of show and is completely serious. But, what if they were never actually expected to be competent enough to invade in the first place? Think about the platoon. You have a lazy Man Child for a leader, an obsessive and insane-but-cute bi-polar foot soldier, a gun crazy, super serious Corporal, a perverted and cruel tech specialist, and an emotionally disturbed ninja. Who would seriously let these people in the military, let alone on a famous invasion, to be viewed as intergalactic poster boys of the Keronian race? People who want to make money. But, who are the real ones working here? The Garuru Platoon. They were hired by the TV company to patrol around Pekopon so nothing actually deadly could come and kill their Cash Cow Franchise. Every Monster of the Week that finds its way into Tokyo was actually planned and purposely let loose on the Keroro Platoon. Most of the enemies, like the Shurara Corps, are actually just actors. Pretty much, everything is a lie, created to make some Keronian CEO very rich.
Private Tamama is secretly a cannibal.How else would he know that Giroro tastes like octopus ball? Clearly, he secretly nibbles away at the platoon when they don't know it.
Fuyuki and Natsumi's dad ran off with Dib and Gaz's mom.Mr. Hinata was a prominent scientist in Japan. He went to a conference in America one year at which he met Dib and Gaz's mom, who had an impressive career of her own at the time but was unhappy in her marriage to Professor Membrane. The two fell madly in love and ran off together, explaining their absence from both canons. Yandere who captures Natsumi's heart by telling her to torture Keroro more), in the anime, she's basically a Canon Sue: everybody loves her, falling all over themselves to impress her, and despite being assigned to a different platoon (the elite Garuru Platoon, natch), she's treated more like a Sixth Ranger. Clearly there's something going on there, and since the manga has already confirmed that the Keron Star has a special effect on its wearer, and the anime is quite fond of Flanderization, they just tweaked that idea to suit their own needs: metaphorically pimping out their chosen Canon Sue.
The whole invasion is actually not for the sake of conquest.
The Angol race prophesized to destroy the Earth are, in fact, benevolent beings, intending to save the rest of the galaxy from human expansion.The introduction of Angol Mois's cousin in Soul Calibur 4 suggests that this was the purpose of their mission, but that their actual observations upon arriving find that there are many sympathetic humans who didn't do anything to deserve death. It also explains why Angol Mois, along with her family the few times you see them, are extremely friendly. Yellow Peril view of the Chinese makes him Unfortunate Implications incarnate.
Zoruru's grudge against Dororo is pure jealousy.In Volume 17, a Flashback reveals how Zeroro and Keroro met: Zeroro was a Shrinking Violet New Transfer Student, and Keroro called him over to play. Innocent enough... except Zoruru was standing right behind Zeroro at the time, and was completely ignored. The flashback doesn't go into any further detail about his motives, but that's what this is for. It's framed to look like Zoruru wanted to get Zeroro's attention, but here's the thing: we don't know how long he was attending that school. So what if he'd always wanted Keroro's attention — or even just for someone to notice him? Yet nobody ever did... and then here comes this shy new transfer student who, without doing anything, immediately makes a brand new friend. Effortlessly — or at least, that's how it looks to him. In other words, it was never about Zeroro at all. Zeroro's just a hapless Scapegoat. (The fact that Zeroro's recognized as the best assassin, yet is completely exempt from the usual assassin's fate of fading into obscurity doesn't help much either.) That's why their latest fight ended the way it did: Keroro finally noticed him, and the result... wasn't exactly what Zoruru expected.
Zeroro never actually assassinated anyone.Volume 17 includes a Flashback where Zeroro's mentor compliments him on earning top marks in all of his exams... then goes on to say that because he's rated as the top assassin, he can't actually become the master assassin. He explains over Zeroro's protests that it's the assassin's fate to be forgotten, then goes on to point out his kindness, stating he'll serve better as "an ordinary soldier". When Zeroro continues to object, he adds "The darkness of the assassin's path is deeper than you can ever imagine." So Zeroro was an assassin In Name Only, probably with little to no field experience prior to joining the Keroro Platoon. He may serve more as a public 'face' for the program, to allay concerns about the military having an assassination branch. This also feeds into the above theory, if Zoruru is aware of his rival's inexperience.
The anime is actually the Cash Cow Franchise produced by Keron Force.In keeping with the earlier WMG about Keron Force actually sending the Keroro Platoon to Pekopon just to spawn a popular TV series, the anime actually is that series. That explains the massive Flanderization, Adaptation Decay and Filler compared to the manga; the manga is a more accurate portayal of events (not available on Keron), while the anime is the result of their efforts and massive Executive Meddling.
In the manga, Sumomo's manga adventures have made her a celebrity on Keron.This is why after the Keron robot gets whacked by Mois, its head opens to reveal a plushie of her. She's become a celebrity (albeit for different reasons from the anime).
Keron is ruled by the Ogdru Jahad.Violent, expansionist frog people who use Humongous Mecha? Certainly sounds like their doing.
Each member of the Keroro Platoon represents a different period in Japanese history.
The members of the Keroro Platoon represent the Seven Deadly Sins.It requires a bit of doubling up, due to their only being five of them, but still:
Shurara's helmet was created using a combination of technology found in the Reality Pen and the Kirurus.Shurara's helmet was a banned weapon on Keron, seeing as it was found too dangerous. It was created so the wearer could use their mind to create all that was needed for a successful take over. A Kiruru-mechanism was placed in it as well that could be manually activated to finish the job. Things did not go as planned, however. Due the the amount of that element that makes the Reality Pen work (Imagine most of the helmet being made of it or an alloy with it in it), the helmet could take on it's own form of sentience, using the user's mind and amplifying the negativity (thanks to the Kiruru parts). The user would eventually loose control and the helmet would activate the take-over switch on its own. It was banned, buried where no one would find it... Until a certain tadpole happened upon it... Ho Yay. He knows about Kichiku Megane and is playing that to his advantage.
Honey-sempai is Tamama in a Pekoponian suit.
Another Invader Zim Parallel: Keroro was exiled to EarthThe Keron military is embarrassed by Keroro and his antics. Rather than giving him a dishonorable discharge, the higher ups (possibly influenced by any of Keroro, Giroro, or Dororo's fathers) decided to dispatch him to Pekopon so he can muck around all he wants without causing trouble. The rest of the platoon is there to make sure Keroro doesn't do anything incredibly stupid or seriously hurt himself, and they're mostly putting up a show for him. Perhaps even the Hinata family is in on it too. The Garuru platoon's "mission" was either a training exercise or to see if Keroro has learned his lesson. dibs on the planet.
Funny Afro Dasonu Maso's song can be defeated too with the Rick Roll or Caramelldansen.In any case, any ugly song by any Dogmatic Space Aliens are just cannon fodder for the awesomeness of the Rick Roll.
Natsumi and Fuyuki's Dad died after watching the cursed videoPerhaps its like this. Little Fuyuki was just developing an interest in the occult, and someone gave him a copy of the cursed video. He watches it, but does not understand the consequences. Natsumi doesn't believe the "stupid legend" so he shows it to his father (Who for the sake of keeping the seasons pattern up will be most likely named Haruka or something similar) Fuyuki unwittingly cursed his father to die from the curse. However, when the time's up, Mr. Hinata is at work, and suffers a fatal heart attack. Everyone thinks he overworked himself to death, but only Fuyuki connects it with the curse. As a result, his love for the occult intensifies.
There is an Ancient Conspiracy related to the keroniansAlong the series there are little hints that keronians have been on earth before the invasion failure, but everytime it appears, it is let unexplained, sometimes rising even more questions.
Keronians have Funny Afros under their hats.Their battle afros that they wear over their hats are a sort of decorative and functional codpiece. This is how Keroro can have a Funny Afro from being caught in an explosion without having had enough warning to put on his battle afro.
Zeroro/Dororo is blind, and "sees" using some sort of ninja skill.This is why he has blue pupils and a complete inability to color inside the lines (such as the time when he and Tamama tried to help Aki finish a chapter of General Frog before the deadline). He treasured his music box because it's a sound-based gift that he received when he was young.
In the anime, Tamama hates Mois not because of jealousy, but because of an unrequited obsession with her.In the beginning back when Mois was first introduced, Tamama did feel jealous felling towards her for being close to Keroro. However, as the series went on, it is made somewhat clear that this "jealousy" made him focus more on "that woman" than Keroro. Somewhere along the way, at least in the subconscious level, he hated Mois not because Keroro pays so much attention to her, but the other way around. Tamama remained believing in the former either because of ignorance or denial.
Mois was rather lonely as a kid.Being a member of the planet destroying Angol tribe, she probably did not have a lot of alien beings to play with due to their fear of the tribe. Keronians, being friends of the Angols, were an exception. This could explain how Mois and Keroro first met and why Mois fell in love with him in the first place.
Mois did not see Keroro again for about two thousand years, or at least what felt that long.According to the manga, Mois is 2000 Earth years of age, yet somehow met Keroro as a child. Normally, this sort of thing would not make sense. But, as confirmed by Fuyuki in the anime in episode 283, time works differently in different regions of outer space. Therefore, Angolans, at least in their sector of outer space, probably mature faster than other species.
Keroro and Giroro were close friends as kids. However, at one point in time they fought and separated over a major issue. They then became Fire-Forged Friends during the Keron War.It would explain why Keroro cut Giroro deep enough to give him a permanent scar and also why they appear to have a closer/different relationship than any of the other platoon members.
Koneko, Giroro's cat, is Kotomine's wife.As we see her in Fate/Zero, she's a Mystical White Hair with gold eyes, which matches both Koneko's real body and her human form. Her fondness for Giroro is partially because he was kind to her, and partially because his voice is one that's beloved to her. Tragic, if you think about it: Either it's reincarnation, where Kotomine/Giroro is capable of love, but not for her, or it's a prior incarnation, and Kotomine's wife was convinced that he did have human feelings because she remembered their Keroro Gunsou incarnations... where, ironically, Kotomine/Giroro wasn't even human.
Natsumi is jealous of her motherAki is so well endowed while Natsumi is not, and she knows it.
Not-So-Obligatory Code Geass TheoryFuyuki combines Lelouch's scrawny weakling nature and Suzaku's good heart. Natsumi is a fierce fighter like Kallen. Momoka is smitten with Fuyuki, just like Shirley is smitten with Lelouch. The Keroro Platoon is a rather goofy version of the Brittanian troopers.
Fuyuki is very aware of Momoka's crush on him, and is equally as shy.Several occassions have shown that Fuyuki isn't so Oblivious to Love, and is perfectly aware of Momoka's crush on him. One episode of the anime had the Lemony Narrator state Fuyuki never gets any Valentine's, but Fuyuki states the narrator is clearly forgot about Momoka. Fuyuki also has a crush on Momoka, but is equally as shy and withdrawn since he believes that many would stare at them since Fuyuki is a commoner (but his mom has a well-paying job), and Momoka is at the top of the pyramid as far as capitolism goes. The Fuyu/Momo ship is quite clearly one of, if not THE most popular ship in the fandom, about as popular as Kero/Tama, Giro/Natsu, and Koyu/Natsu. It's also the closest thing that the anime and manga have to a canon couple (when the main characters are concerned). Leave it to the fanfiction writers and the fanartists to fix this unresolved subplot!