“There there! That’s the one!” Keroro was excitedly pointing all over the device Fuyuki was holding, with nothing in the way of useful instructions. “The one next to the one with that one shape, you know. Press that first!”
       
       The kero ball in the boy’s hands would have been hard to figure out even with an instruction manual, but with Keroro’s instructions it was completely impossible. Fuyuki was just uselessly turning the thing around in his hands. Every time he did Keroro pointed somewhere new. “W-Wait, Keroro… hold on.” While he fumbled with the ball looking for the button with the one shape, he had to wonder how Keroro had talked him into this. “Are you sure this’ll even work?”
       
       “Of course, I’m sure!” Keroro smiled and wagged his finger. It was a toothy smile, one that would have made anyone with an ounce of good sense suspicious. Fuyuki didn’t hold that ounce of good sense, at least when it came to his best friend, so he smiled right back. “I wouldn’t have had you dig out my old superweapon if I didn’t think it could solve all your problems, right?”
       
       Fuyuki nodded and looked back down at the odd black ball. Keroro had said it would help him with his reputation. Coolest kid in town, were his words. He hadn’t explained how, sure, but Fuyuki trusted his friend. So, he found a button that looked right and hovered his finger over it. “So, the one with the shape?”
       
       Keroro’s previous unhelpful enthusiasm came right back, and he stopped his finger wagging to point right at the ball again. “Yeah! That’s the one press it three times long, then one time short!” 
       
       Still unsure if he was even pushing the right button, Fuyuki nodded and followed the alien frog’s instructions. There was a brief pause after that, or more of a long pause, actually. It lasted long enough for Fuyuki to wonder if he’d done it right. Just to be safe, he pressed the button again. 
       
       That was when a blast of purple light hit him square in the face from the ball’s antennae. It nearly sent him reeling backwards, blowing the hair out of face. It even blew his pajamas back. For a moment, it felt like it would blow them right off of him. Keroro seemed shocked by the blast too. He very nearly fell over, only balancing himself thanks to some wild pinwheeling of his arms. 
       
       Then, just as suddenly as it started, the light and the blast of air that came with it stopped, leaving behind a dazed Fuyuki and a few uncomfortable afterimages. “Ugh… wh-what was that… Keroro?” The afterimages only lasted until he could blink them away, but the dizziness stuck around. The whole room was spinning. He tried to center himself by keeping his eyes on his Keroro, but the frog was shaking even more than everything else. The shocked look on his face wasn’t really comforting either. 
       
       “W-wow… that was fast…” Keroro stared wide-eyed at Fuyuki. Suddenly he was looking a lot less gung-ho about the idea of using the kero ball. Fuyuki knew it should have worried him. He thought he should be panicking in fact. At the time though, the only thing he could feel was discomfort. It was like a haze that covered his whole body and clouded his head.
       
       He glanced down almost reflexively as if he was trying to see through the cloud. What he did see shocked him, but not enough to clear the haze. His hands had taken on a blue color and were starting to shrink. He watched dizzily as his fingers pulled in, and he was suddenly aware that his clothes were starting to sag, feeling bigger and heavier on him than they had before. 
       
       Now that Fuyuki could see what was happening, some other sense started to poke through the cloud in his head. He blinked and tried to wiggle his finger and toes but doing so was getting harder by the second. His fingers were rapidly shrinking back into almost nothing. Right now, they were just small blue nubs on his palm, and they were getting smaller. He couldn’t even see his toes, just the slightest shape of something wiggling at the end of mostly empty socks. When he tried to stretch them, they felt stuck together. 
       
       “K-Keroro…” Fuyuki groaned, just a hint of his worry broke through. He lifted his eyes to glance at his friend, but just looking up brought the dizziness back even stronger. He only got the barest look at Keroro lunging toward him, hand outstretched, before he nearly fell over. He dropped the Kero ball when his hands darted out to his sides to catch him. The moment he did, his shirt fell from what was left of his arms, pooling around him. “Wh-what’s…” He thought to ask Keroro what was happening, but the words weren’t coming out. 
       
       His friend’s first response to his mumbling was to grab the clothes out from under the boy. Fuyuki was briefly thrown off balance, and his head fell back as his vision blurred up with tears. His head felt too heavy to move, so he kept staring at the ceiling. It looked really far away. “D-Don’t worry, Fuyuki, it’s all cool, right?” Keroro was shouting but it sounded muffled. 

       Fuyuki was only vaguely aware of the frog reaching over and pulling him out of his shirt at first. Then, before he knew it, it all hit him at once. Keroro’s hands under his arms felt so big, and they lifted him with so much strength. He knew something was wrong, but now, blinking away the blur, he finally got exactly what. He looked down at himself, first glancing at an arm, then at his back. Everything felt cold and slimy, his skin had turned white and blue, and looking back confirmed that a tail had popped free from his back at some point. 
       
       He gave it a little wiggle, stumbling back a step. Keroro held him tighter then, but he barely noticed. “I’m… a keronian?” He wasn’t sure how to feel. There was still a bit of a daze, but his eyes did start to widen. 
       
       “Uh… y-yeah! C-cool, right?” Keroro gripped him even tighter, and when Fuyuki turned back to him, he was sweating. “N-now you can be part of the platoon! S-super cool… and totally my plan.”
       
       Fuyuki stared wide eyed at his friend for a moment as what was left of the haze vanished and he got to grip with his feelings. He started to shake, and eventually had to steady himself by slamming his new hands on Keroro’s shoulders. The green frog shook, but remained steady, and he kept smiling. For a moment, Fuyuki was amazed by how strong his friend felt at this size, but the need to shout at him was too overwhelming to be distracted. “S-Sarge… that’s awesome!”
       
       Keroro’s smile broke that instant. His eyes went wide for a second, and then it came back, much brighter than before. He was smiling so big and bright it looked like he might cry. “R-really?!” He reached out and clasped Fuyuki’s new hands. The boy was a bit surprised by how tight the sarge’s grip was. “Ha! That’s a relief. I was so worried you’d be mad when the brainwashing didn’t work.” His eyes closed and he sighed obviously with relief as his grip around his friend’s chest loosened. 
       
       Fuyuki was briefly thrown enough to ask after what Keroro had just said, but he was pretty sure the dizziness from before was still making his ears ring or something. So, he just opted to check and make sure he’d heard right. “Uh, brainwashing?”
       
       “Oh, it’s nothing.” Keroro laughed off the question with his smile before his eyes popped back open and his hands shot up to grab Fuyuki by the shoulders. “Anyway, now that you’re officially a member of the A.R.M.P.I.T. platoon, we can do all sorts of cool stuff. I bet we’ll conquer the planet in no time with you on our side, right?” 
       
       “Uh… y-yeah. I’m still not sure I can just let you conquer earth now that I’m a keronian, sarge.” Fuyuki nervously smiled and laughed before looking around. With the haze gone he could really appreciate just how much had changed. His room was enormous, and he couldn’t even see over the balcony of his window anymore. His bed and blankets were so big that he couldn’t help but get a giddy feeling as his feet bounced on it, sure that it could really be a trampoline at this size. He couldn’t even imagine sitting at his desk anymore. 
       
       Most importantly though, he was able to be eye to eye with his best friend. Eventually his eyes settled back on the sarge. He was super big now too, maybe even slight bigger than Fuyuki. More than that though, he looked different somehow. Fuyuki was pretty sure he looked shiner, maybe a bit manlier somehow. Fuyuki reached out to touch Keroro’s moist face, then his chest. His eyes reflexively ran over Keroro’s body while he tried to get a sense of what had changed. Though the first thought that ran through his head was that the frog was somehow more handsome. 
       
       Then his eyes caught something he’d definitely never seen before around the frog’s groin. There was just the smallest bit of pink. Once he saw it, the haze came rushing back, and he nearly lost balance again. He only stayed up thanks to Keroro holding him. “F-Fuyuki!” The frog followed up by shaking him until the daze lifted and Fuyuki could look him in the eyes again. The concern on his face and the way the sweat shined against it was definitely registering as attractive now. “A-Are you okay.”
       
       Fuyuki didn’t have an answer for that one. He’d never thought of Keroro as attractive before. He was cute in a merchandisable way, sure, but actually attractive? He’d never even really thought of another guy as attractive before. Right now though, the frog was actually making him feel horny as he felt the slimy skin of his chest against his flipper. He could feel butterflies stirring in his stomach, and when he blinked Keroro took the place of a pinup model in a magazine. 
       
       “K-Keroro… wh-what’s that?” Fuyuki had a pretty good idea what it was, but asking was an excuse to look down again, this time with Keroro’s eyes following his. The haze didn’t overcome him this time, but it still struck him along with an increase in butterflies.  Keroro’s dick was a single pink muscle poking out of a little slit right below his groin that Fuyuki had never noticed before. It was just a little triangular nub right now, but Fuyuki had a feeling based on some internet searches that there was more to it than what he was seeing right now.
       
       “Uh… keke… D-don’t think about that, buddy.” Keroro was sweating so much that Fuyuki could feel it running down his chest. “I-it’s just a normal reaction c-cause you’re so cute- I mean cool!” Keroro started to shake and tried to laugh it off with his usual keros. Fuyuki barely listened. He was distracted by exploring his own new body with a hand, sliding it down his own groin until, sure enough, he found a slit. When his hand slid into it, he groaned and Keroro sputtered. 
       
       “Wh-whoa!” Fuyuki’s eyes rolled back until he was looking up at Keroro again. The frog looked absolutely stunned and his eyes stayed firmly on Fuyuki’s groin. He knew why, he could feel his cock coming out the moment he touched his slit. It wanted out desperately, loading Fuyuki up with shivers and forcing him to work the slit and pull on the shaft until it squirmed out completely. The whole way he was groaning intensely. Eventually, he had to close his eyes and just hold on tight to Keroro. “M-man… alien biology is… awesome…”
       
       “F-Fuyuki!” Keroro shouted, and Fuyuki’s eyes shot open. Now Keroro was looking right at him, eyes seemingly wider than Fuyuki had ever seen them. He looked shell-shocked, and he was squeezing so hard that Fuyuki’s shoulders started to hurt.
       
       “I… s-sorry Keroro…” Now it was Fuyuki’s turn to shake. Embarrassing as the situation was though, he couldn’t bring himself to pull the flipper off his dick. His dick felt way more sensitive than it ever had before. It was almost painful, but at the same time it was so easy to move over it. It was slick and slimy and so very easy to run his hand across it. He was masturbating in front of his friend before he could stop himself. “Ah! S-sorry!”
       
       Keroro’s eyes slammed shut in front of him. Fuyuki was sure it was because he was disgusted, and he forced his hand to stop moving out of embarrassment. Then, Keroro’s face lit up bright red and his eyes opened hazily “O-okay, Fuyuki…” He whispered so quietly at first that Fuyuki could barely make out his own name. Then, the little blue boy felt the sarge’s strong hand sliding roughly down his arms. They didn’t stop until they reached Fuyuki’s own hands, which meant one ended up right on the young frog’s dick just in time for Keroro to whisper again. “Let’s do this!”
       
       Fuyuki let loose a squeaky scream. Keroro’s grip was just as strong around his new sensitive appendage, but it still slid smoothly over it, guiding Fuyuki’s hand alongside it. Fuyuki’s knees felt weak as he squeezed Keroro’s hand for stability. “S-Sargent!” He knew he would last long. He never had before and that was when he was human and alone. This was so much more intense. It was almost frightening, but he trusted Keroro. So, he leaned into the green frog, even burying his face in his shoulder while he continued to mumble his name. 
       
       When he did cum, he felt his whole body quiver all the way down to his tail. The feeling was so overwhelming he seemed to black out for a second, coming to with his head lifted from Keroro’s shoulder, loudly screaming for the sarge. He could feel himself squirting, though he had no idea how much. It felt like way more then he’d ever cum by himself. 
       
       And once it was done, he collapsed. He was still on his feet, but that was only because Keroro caught him, wrapping an arm around him before he felt again. The other hand stayed on his dick. “Kerokero…” Fuyuki was panting, but the frog’s laugh rang clear. With his weight pushed against Keroro’s chest, it even seemed to echo through him, making his tail quiver again. “You haven’t done this before, have you, Fuyuki.”
       
       Something about the way he spoke sounded sinister, but Fuyuki didn’t really care. Absentmindedly he let himself rest against Keroro. He even reached out to hug him, as best as their slimy bodies would let him. 
       
       That’s why he was somehow unprepared when his back suddenly slammed against the mattress beneath them. Though, he wasn’t terribly surprised after that to see Keroro staring down at him. The blank, feral look on the green frog’s face as he drooled over him was somewhat unnerving though. “Uh, w-what’s up, sarge?” 
       
       “Kerokero… I can’t believe you’re a virgin!” Keroro smiled and backed away. Fuyuki blushed at the mention of his virginity, but then turned beat red when it dawned on him why Keroro cared. When the alien lifted his legs and slid his cock against his tail, his head felt so hot he was pretty sure it might burst. “Well, then pekoponion, let me show you how it’s done.”
       
       Fuyuki quivered as Keroro’s dick rubbed against him, searching his underside for something. It took the young frog an embarrassingly long time to figure out just what, and once he had, Keroro had already found it. “W-Wait! Th-there’s no way that’ll work!” He squirmed as the slimy shaft slid against his anus. He’d just now realized it was still there in his new body, tucked lower in his slit just under his tail. Even if it was in a knew place though, Fuyuki knew one thing about it from his knowledge on human anatomy. “Th-there’s no way that’ll fit!”
       
       Keroro just continued to smile down at him and laugh, steadying his quivering hips with that strong grip of his. “Trust me, Fuyuki, it’ll fit.” He laughed again as his dick slid its tip against Fuyuki’s entrance. The little blue frog wanted to shake and squirm when he felt it press against him, but Keroro held him tight. So he just took a deep breath and grimaced, choosing to trust his friend. 
       
       The grimace didn’t hold long before it was replaced by another squeaky-voiced shout once Keroro slipped inside. The sarge slipped in with remarkable ease considering how Fuyuki squeezed against the entrance. His hard, almost clumsy thrusting was facilitated by the warm slime all over his cock, as well as, Fuyuki suspected, some of his own cum. 
       
       “K-Kero!” The sarge shouted and shut his eyes. Once Fuyuki was able to open his, he saw the feral look had left, replaced by the familiar dopey smile that the frog wore when he’d just found a new Gundam. It was comforting to see that goofy grin. The penetration was painful. Fuyuki felt like he was full to bursting and every new thrust felt like it was filling him more and more, but that dopey smile somehow made him feel safer. 
       
       It wasn’t enough to contain all his shaking though. The feeling of being filled was overwhelming, and the way that Keroro thrust didn’t allow him to ever get used to it. His cock throbbed painfully at the intrusion as well, feeling even more sensitive than it had been. Nothing was touching it, but it felt like it was constantly cumming. Unable to deal with that sensation, all Fuyuki could do was grab the sheets beneath him and try to stabilize himself by watching Keroro’s smile. “S-Sarge… ugh…”
       
       When the smile vanished, his stability vanished to. One more boisterous shout of “Kero!” accompanied Keroro’s orgasm, and soon the little blue frog was feeling even more full than before. He could swear he stomach swelled up as Keroro filled him with his alien cum. All the while he kept staring up at his friend, practically pleading. At least he still looked goofy now as he drooled, looking more like a dopey dog than some feral monster. For Fuyuki though, that only offered a small comfort as he gripped the sheets and panic struck his mind. 
       
       Eventually, Keroro finished, casually pulling out of the young frog and wiping his brow. He left Fuyuki there without a thought as he sat back on his hands and sighed. Fuyuki sighed as well trying to catch his breath as he felt the sarge’s load leak out around his tail. After he’d lost all he thought would come out, he too sat up, groggily staring at his friend. The haze from before was back, stifling a few panicked thoughts. So, he couldn’t speak.
       
       Thankfully, Keroro broke the silence. “Holy cow, Fuyuki! That was great! You should have joined the platoon a long time ago!” He laughed and gasped a second more before he opened his eyes. Then panic set in for him as well, along with some genuine concern. Fuyuki was crying.
       
       “Y-You better take responsibility, Sarge!” Strength surged back slowly, allowing him to shout at the green frog. He grabbed the sheets for stability and leaned forward to scold him. “I-if I get pregnant from this! I-it’s your fault!”
       
       At that moment, the panic vanished from Keroro’s face, though he did still look concerned. “Oh wow, you really are new to this huh, Fuyuki?”
       
       “Sh-Shut up! I don’t know how alien frog sex works!” As strength surged back, Fuyuki was eventually able to grab at Keroro’s shoulders, and even push him down on the bed. Now he was more embarrassed then panicked though, which definitely helped. “Y-you didn’t lay eggs in me or anything, right?”
       
       “Kerokero!” Keroro smiled up at the boy turned frog. “Okay, so, I guess there’re a few new lessons you need on Keronian biology. Or I need a few new lessons on Pekoponians…” Still laughing, he wrapped his hands around the boy above him, and his cock swerved, seemingly deliberately pressing against Fuyuki’s. That sent the blue frog quivering again. “How about I teach you a few more things, huh? I know a few cool tricks!”
       
       The biology lesson that ensued lasted long into the evening. Fuyuki wasn’t sure exactly how much he learned by the end, but Keroro assured him that he was definitely a lot cooler now with all the new tricks he’d practiced. 
       
       The new keronian wasn’t sure if he agreed about the tricks, but by the time it was over, he had to admit his new biology was way more awesome than the old him.