Sgt Frog: The GiroNatsu Chronicles (Unofficial Reboot)

By Adventuremaker21 (Original concept by TheLadyLala)

Chapter 1: Change for the better (or for worse)


Authors Note:

Guess who's back in this fandom? This Guy! Anyway, this fanfic is more of an unofficial reboot of the first fanfic I've read on this website as a gift to the original author, TheLadyLala. Now with more adventures that line up with the tone of the show and maybe some ships here and there (It's in the title, in case you've missed it). Now sit back, relax, and have those Vietnam levels of flashbacks as you remember something long forgotten.

P.S., Saburo's not gonna end up like the last fanfic.


Inside the model section in a toy store in Tokyo, Japan, right in front of the huge selection of Gunpla, stood a man in a business suit. But upon further inspection, there was a weird green alien frog head on top, armed with a yellow hat with a red star on top. To the average person, they think it's a skin condition, but in reality, he was actually Sargent Keroro, the leading officer of the Advance Recon Mission Preparatory Invasion Terror Platoon, ironically shortened to ARMPIT platoon, a team of alien frogs from the planet Keron, sent to prep the invasion of Earth.

Instead, he's thinking about and debating what Gunpla to get while dressing like an oddly familiar Steven Spielberg cartoon from the '90s.

"Soon..." Keroro whispered to himself. "Sooner or later, I will own all of you beauties." He finished while laughing 'kerokerokerokerokero'.

"Mommy, look at the strange man's head," A kid who walked into the aisle said as he pointed and yelled at him. Fearing for the worse, Keroro stood still, daring not to move a muscle. If he were to be discovered here and now, then the entire invasion plan would fall to ruin. All the model kits he worked on wouldn't be attended to anymore. "It looks like he's been taken over by an alien."

At that moment, the boy's mother came to him and scolded him. "You know it's rude to call people by what they look like." She looked at Keroro and chuckled nervously. "I'm terribly sorry about that. Ted just doesn't know any better."

"No No, it's ok ma'am," Keroro chuckled as he let her know that there were no hard feelings about the boy's comments towards him. As he and his mother turned and walked away, Keroro let out a sigh of relief. "That was close," Keroro said to himself in his normal personality. "Way too close, if you ask me."

(I can assure you, Frog Brain, that nobody was asking.)

"The invisibility function has a worse battery life than an iPhone, and these suits make us look like that one weird American cartoon," Keroro listed. "There must be a better way to cheese Gunpla buying without paying extra for shipping and handling." And at that exact moment, the TV on the counter was showcasing an old episode of Ranma 1/2 and sees how the father turned into a Panda. Seeing this in action slowly started making Keroro's rusty-dusty gears in his frog head. "Of course, it's all so clear now. The answer was so simple, I was too smart to see it."

(I'm pretty sure those 5th graders out there are smarter than you at this point)

Soon, Keroro quickly buys some Gunpla as he quickly rushes back to the Hinata residence to see if a certain curry-smelling Keronian was there. Popping out of his man-suit and carrying his stack of unopened models down to the secret HQ of the ARMPIT platoon. Sitting down there was everyone's favorite kissass Private Second Class Tamama as he was so bored, he was resorted to playing Guess Who with his so-called rival, the ditzy yet powerful Angol Mois.

"Uncle," Mois asked of him as he rushed in. "Are you doing alright?"

"Did you rush home to take a dump?" Tamama added on. "It's no shame, I do it all the time. Of Course, when I do it, I get-"

"Not now, my faithful and probably constipated friend," Keroro assured him as he gently placed his models down. "I HAVTA REPORT THE FROG OUT OF THIS TO KULULU!" As he did so, he rushed straight to the refrigerator to access the Sargent Major's laboratory. Both Tamama and Mois looked at the stack and then at the trail of smoke between it and the fridge.

"If he's willing to prioritize the invasion then what appears to be P-Bandai exclusive Gunpla, then it has to be huge, right?" Tamama asked of her as she slowly nods.

Down, like way downstairs, sat in a dark room with a few screens on display, all of the bathroom and all of a certain human woman. And watching this woman was the previously mentioned Sargent Major Kululu.

(Look at this creep watching stuff like this like it's a Saturday night. YOU KNOW ITS TUESDAY AFTERNOON, RIGHT?!)

Slurping down a bowl of curry, he watched as this woman undress as she was ready to shower. And when it was about to get to the best part, Keroro crashes through the door as he tripped and landed on his face.

"Owie...," Keroro softly exclaimed. Hearing the crashing, Kululu chuckled his signature 'kukuku'.

"So what brings you by my theoretical chocolate factory?" Kululu laughed while he turned around in his chair.

"Ok, here goes nothing," Keroro said as he picked himself up comically.

(Oh, this should be fun.)

"So you know how crappy the battery life is for our invisibility tech, and the pekoponian suits make us look more out of place than a Transformer on a Gunpla shelf," Keroro explained seemingly all within one breath. During his rant, both Tamama and Mois peeping in, wanting to mutually support this green otaku.

"What do you think he's saying?" Tamama said to Mois curiously.

"I think he said that Transformers are better than Gundam," Mois answered as she can only hear bits and pieces of what her uncle is trying to say.

"So what is this all really about?" Kululu said, easily bored of what his so-called 'commanding officer' is trying to say to him.

"So, I finally found a way to fully give us all an advantage. And by the time we're done conquering this planet, they won't even know what'll hit them because..." Keroro said as he was trying to simulate a drumroll with him patting his head, spinning on his froggy heal, and then posing dramatically. "KULULU, AS YOUR COMMANDING OFFICER, I ORDER YOU TO FIND A WAY TO MAKE US TURN INTO PEKOPONIANS AT WILL!"

The news of this shocked both Tamama and Mois as they cannot believe what they're hearing. Kululu, on the other hand, was laughing harder than any of them have ever heard before.

"Sounds fun, kuku," Kululu said as he finished his curry. "Give me a few hours and ill present to you with what I can think of." He finished as he turned around to work on ideas. Closing out of the window of the woman bathing because he already has it recorded. This dumb yet fascinating plan, however, could not.

"Thanks, Kululu," Keroro sang at him as he skipped out and sees Mois and Tamama. "Ah, perfect timing, you two. We must now kill time before the game changes for good."

"Yea, we heard, Uncle," Mois said as she joins him.

"You mean we're really gonna gain the power to turn into Pekoponians at will?" Tamama said excitedly. "No more pekoponian suits besides the obvious beach and festivle fanservice?"

"Exactly, my loyal Tamama," Keroro said. "Oh, would you be a good soldier and give me some cow flesh? Preferably the Maccy D's kind."

Tamama and Mois saluted to the green frog. "SIR, YES, SIR!" They told him as Keroro chuckles.

(This sounds like a recipe for disaster. Now let's jump to the school because really, who wants to see a frog alien build gunpla models.)

Over towards the Kissho Academy, Fuyuki was writing something on the board while Momoka was watching in awe at what he was writing on the board. He was writing 'First Offical Meeting' on the board. After finishing it, he turned around and clapped his hands. "All right, everyone, since now that we have 5 members, we can officially form the Occult club." As he finished saying that, a hand was raised, and that hand was connected to Natsumi, his angry sister.

"Uh yea, nerd boy, why did I have to come here," she almost yelled at him, clearly not in the mood to stay here.

"Because he asked politely," Koyoki said, sitting next to her while munching on a cookie. "Also he had cookies."

"Yup, with you two, Vice president Momoka, and Saburo-"

"Saburo?!" Natsumi almost yelled out as her face turned as pink as her hair. "He's here?!"

"Oh yea," Fuyuki said, excited as he points to him in the back of the room, leaning back on a chair. "All I had to do was ask."

"Plus, I owed him one," Saburo said as he tilted his head up, smiling slightly.

"With all 5 of us here, the school can now recognize us as a legit club," Fuyuki said with stars in his eyes. "Now let's get started."

(Ok, do we really want to see them go through the meeting together like they're the SOS Brigade? Because, honestly, they're not that far off. Hey, I got an idea: Why don't we see What Kululu is cooking up? That'll be fun.)

Deep within the lab, Kululu was making some last-minute adjustments towards the new gun, which looks like the Animal Animializer for some reason.

"Kukukuku, I knew there was a use for all this hair from the woman, kuku, It's so much easier to get them from the shower drainage than when she sleeps," Kululu said as she turned the hair into goo as he next turned towards a vial of blood as he examined it. "And it's so easy to check for Keronian blood samples in this house when Natsumi's around, kuku." Doing the same to the blood into goo, he then mixed them together and loaded them into the gun that used to be the Animal Animalizer. And at that exact moment, Keroro was crawling through the doorway, easily melted as he slithered up to Kululu.

"Is it done yet?" Keroro asked, only to get a laughing response from Kululu. Turning around after finishing the gun, he keeps laughing.

"Ah, Sargent, speak of the devil and it shall be yours," Kululu said as he presented it to him. At first glance, Keroro's eyes lit up as he plopped up, and grabbed the gun.

"Gimme, gimme, gimme!" Keroro said as he pointed it at himself, ready to test it on himself as Kululu started laughing at him.

"You sure you want to try it on yourself, Sir?" Kululu said, ominous. "I Still haven't tested it on anyone."

"WHAT?!" Keroro said, shocked as he held the gun back. "WHY THE FROG HAS IT NOT BEEN TESTED YET!"

"Because I just finished it not even a second after you came in, Kuku," Kululu said as he took it back. "This here is my greatest invention yet: The Peko-Keroinizer. One Blast with this turns a Pekoponian into a Keronian and vice versa, granting them the ability to turn back at will. The only reason I haven't tested this out yet is that the effects are irreversible, even by my standards."

"Oh..." Keroro said, a little disappointed. "So who do we test them on first?"

"Kukuku," Laughed Keroro. "Oh sarge, if you really knew me, then you'd know who I want first."

"And you know who I want to do first," Keroro agreed with him as they put operation: Mile Shoe into effect.

(Come on, Mile Shoe? I could come up with a better name than that.)

About an hour and a half to two hours later, the members of the Occult Club were walking out of the school grounds as they were just chatting about the weather.

"Ugh, is it that late already?" Natsumi said as she checked her phone. "Come on, Fuyuki let's head home."

"Actually, sis," Fuyuki started to speak. "I'm heading over to Momoka's place to plan new club meeting ideas."

"It'll be me and him, all alone," Momoka said slowly as she was in some sort of trance.

"I'm gonna head over to my place and prep for tonight," Saburo said, chill as ever. "I'm doing a special on One Piece's 1000th chapter, and I want to make sure I get my poem on Boa Hancock just right."

"And tonight's Shogi night with Dororo," Koyuki said as she prepares to leave. "It makes him feel like he's wanted compared to his platoon."

"Say hi to him for me," Fuyuki called out as they went their separate ways.

As Natsumi was walking home, she was thinking about what could await her when she arrived. Another visitor, perhaps? Or maybe Some elaborate scheme Keroro whipped up out of stupidity? Whatever it was, she shrugged it off and made sure to walk in the front door. but upon taking that first step, she was instantly sucked down towards the vent secretly installed beneath the doormat. down and down she goes until she lands in one of those strapable chairs. Suddenly, she was tied up by robotic clamps and made sure she would get out. As Natsumi struggled, she glanced next to him and saw Giroro in her same situation, looking furious.

"You're here, too?" Natsumi said, shocked to have both her and him captured so easily.

"Surprisingly, Yes," said Giroro, in his usual tone. "I was caring to my sweet potato farm, the one other hobby I have on this mudball besides weapon cleaning when suddenly I was swept up here like you. How did you get caught?"

Natsumi blushed and looked away. "I came home and didn't watch where I was going." As she said that, she looked furious again. "BUT I DO KNOW WHOS RESPONSIBLE FOR THIS!" Suddenly, they both heard a 'Kukukukuku'.

"Oh, do you now?" Kululu said as his chair descended to them and in his arms, was Keroro and the Peko-Keronizer in his green frog hands.

"Wait, a join mission?!" Giroro said between his teeth. "What kind of unholy madness did you two come up with?!"

Keroro jumped out of Kululu's arms and showed off his new gun. "Oh my dear corporal, it's quite holy. This gun is known as the Peko-Keronizer, and it does exactly what it says."

"No I don't know what it does," Natsumi yelled.

"English, motherfucker, do you speak it!" Giroro yelled as well.

"It IS simple. This gun grants the power to turn Pekoponians into Keronians, and Keronians into Pekoponians. It turns you into the opposite form first, tho," Kululu explained to them.

"THIS WILL BEGIN A BRAND NEW ERA FOR THE INVASION!" Keroro said as he fired the gun at them at the same time, blinding them in a flashy opal-colored light.

"YOU STUPID FROG!" Natsumi yelled out in rage.

"I WILL KILL YOU!" Giroro said as well as the light dimmed down for the both of them. Sitting in Giroro's place, sat a human teenage boy with a blonde buzzcut, a familiar scar over his left eye, a red vest with a white undershirt, jeans with his belt, and red and white sneakers with his skull logo on it. Sitting in Natsumi's place was a bright orange Keronian with a hat that looked like Natsumi's signature hair, and has a matching sun insignia on both hat and belly.

"I-it worked?" Keroro said in shock as he speechless as he soon jittered in place. "IT ACTUALLY WORKED! Now no one can stop the mighty ARMPIT platoon, and look, we have a potential new member."

"Of course it didn't work you stupid fro-ooAAAAAAAHHHHHHHH!" Natsumi said as she looked down at herself. "MY WORST NIGHTMARE IS TRUE! I AM A STUPID FROG!"

"I'm taller, better built, and look like Chris Evans with a buzzcut. THIS IS UNACCEPTABLE! IF WERE GONNA RULE THIS WOLRD, ID RATHER DO IT IN MY OWN KERONIAN BODY!" Giroro roared as he broke through the robot restraints as he practically launched himself towards Keroro. "TURN ME BACK, OR SO HELP ME, I WILL STUFF YOU IN A BOX AND SHIP YOU TO ABU DHABI!"

"EVERY MONDAY WITH YOU!" Keroro screamed in terror as Kululu was laughing as he retracted himself into the ceiling. "KULULU, WAIT, COME BACK!"

"Sorry sarge, but you should have stayed in my lap, kukukuku," Kululu chuckled as he zipped back upstairs.

"TRAITOR!" Keroro yelled as he was implanted into the wall by a furious Giroro. Giroro then sprinted towards Natsumi and yanked her restraints off with his new human strength.

"Are you all right?" Giroro gently asked her as she hopped out of the chair.

"Besides the fact I'm a stupid frog now, I should be good, but he's not leaving this basement alive," Natsumi threatened as both of them went up as Natsumi yanked Keroro out of his lodged placement.

"Ph-ew," Keroro said with some scratches on her face. "Thanks, guys, I really owed ya one." He said as he sees two pissed-off people as he knows what's coming. "Mommy..."

"Shall we," Giroro said, holding Keroro by the head in front of Natsumi like a sandbag as Natsumi nods, cracking her new froggy knuckles.

(one brutal beatdown worthy of the Joestar mark later.)

Both Giroro and Natsumi were heading back up to the main living room, trying to come to terms with what happened. Natsumi sat on the couch as she started tearing up and crying.

"Natsumi..." Giroro said, trying to confront her.

"T-that frog ruined my life," she said in between tears. "I can't see my friends, I can't go to school, I cant kick ass in sports..." she said as she went back to crying. As she cried, the door opened.

"Hey, I'm back," Fuyuki said. "We got our homework done early, so I decided to come home before mom did. For some reason, I had to do my English homework while holding Momoka's hand. It was pretty sweaty." He walked into the living room to see the crying keronian and the comforting human. "Oh hey, a new frog," Fuyuki said as he sat down next to her. "Hey there, I know this must be tough, but It'll be alright. You'll see, Earth ain't so bad for a space frog." Fuyuki said as he picked up Natsumi and hugged her. "Besides, I never met a female keronian before. But hey, as long as your on earth, you could teach us."

"I don't think that's what she needs, Fuyuki," Giroro said, astounded that even though Fuyuki is smart and his heart is in the right place, he's also an idiot.

"Wait a minute..." Fuyuki said, piecing it all together. "Giroro? Is that you? Why do you look like Terry Bogard with a buzzcut."

"That genius found a way to turn Pekoponians into Keronians and vice versa, and they decided to test it on us," Giroro told him.

"If You're a human now, then that means..." Fuyuki said, turning his head to the orange frog. "NATSUMI?!"

"Yea, the frog did this to me for some reason and-" Natsumi tried to explain as she quickly got squeezed into a hug.

"THIS IS INCREDIBLE!" Fuyuki started ranting. "WHEN YOU CHANGE BACK, YOU HAVE TO TELL ME WHAT IT WAS LIKE BEING A DIFFERENT SPECIES."

Natsumi pulled away from the overjoyed Fuyuki and took a deep breath. "First of all, I still need to breathe. Second of all, that yellow bastard said this was permanent which means I cant tower over the stupid frogs BECAUSE I AM A STUPID FROG!" As she was ranting about how Keroro And Kululu destroyed her human life, she started to glow and grow back to her human form, complete with clothes. Because of this new weight, Fuyuki fell back on the couch.

"WHOA, YOU CAN SHAPESHIFT?!" Fuyuki said as his eyes lit up. "THAT'S EVEN BETTER!"

"How did you do that?" Giroro asked in awe.

"I was ranting and thinking about me being a human and suddenly I'm sitting on my brother," Natsumi honestly explained.

"All in the name of the paranormal," Fuyuki said, clearly in pain.

"Wait, let me try," Giroro said as he recalled a memory from his childhood as he changed back into a Keronian. "With powers like these, we would finally be able to blend with the Pekoponian populous AND FINALLY CONCOUR THIS WORLD!"

"And Natsumi can help further develop the theory of what it's like to be a member of two different species for the Occult Club," Fuyuki said, just as excited as Giroro.

"Do I have to?" Natsumi said as she got off her brother.

"It's either that or tell mom that you can turn into a frog at will," Fuyuki said, shocking Natsumi as their mother, Aki, is a huge fan at being inspired and if she ever found out, she would ask her way too many questions about her powers.

"You wouldn't..." Natsumi said, getting a little ticked.

"That is cold, Fuyuki," Giroro said with a hint of respect in his voice.

"Fine," Natsumi said, giving in. "But nothing NSFW, ok?"

"You got a deal, Natsumi," Fuyuki said as she shook her hand.

(And so, ends another day at the Hinata home, only this time, nothing goes back to the way they were. You better get ready, viewers, because things are about to change.)