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Border! To Assassination Classroom!

Summary:

In a world where 70% of the moon was vaporised into thin air. Class 3-E may be having more visitors to their classroom than expected.....

or

Border agents Yuma and Jin helps Class 3-E with their mission to kill their octopus teacher!

Notes:

Hello! This is my first ever fic lol. I've never written a fic before, but I just really wanted to see a crossover between these 2 series, so here we are. Sorry for any grammar mistakes or pacing issues! I'll try to improve my writing more as this goes on! There are no fixed updates. I write a new chapter when I feel like it or have ideas. This story is cross-posted on Wattpad too! Same title under username: @i_NeedLife

Chapter 1: Chapter 1: Welcome Border

Summary:

70% of the moon is gone, and class 3-E is tasked to eliminate the target that vaporised it. Border decided to send 2 agents to support their mission.

Notes:

The first chapter! The writing is probably pretty bad here. Hopefully it's still readable. Also we need more world trigger fans!

(See the end of the chapter for more notes.)

Chapter Text

Third-person POV

“Whoa, look, Osamu, the moon turned into a crescent, I didn’t know the moon could do that,” 

Yuma says in excitement before noticing the shocked look on Osamu’s face. 

“What’s wrong?”  Osamu turns to the confused Yuma before grabbing his shoulder in distress.

“You don’t get it, Yuma, the moon isn’t supposed to do that!” 

 

~line break~

 

“Breaking news, 70% of the moon has been vaporised into thin air. Experts are still trying to figure out this shocking event. Will we be stuck with the crescent moon for the rest of our lives?”

The people in the Tamakoma branch stare at the TV in silence. I mean, what exactly can they say? This has never happened in history. 

“Is this the work of a neighbour?” Osamu asked Yuma in curiosity, 

“No, I don’t think so, the trion soldiers shouldn’t be strong enough to do this, and I don’t think this is a work of a trigger, not only that, I don’t see how the neighbours would benefit from destroying the moon anyway.” 

“But if it isn’t a neighbour then who….” Osamu got interrupted by Jin clapping his hands to get their attention, 

“Ahem, well, this is certainly shocking, but for now let’s just get some rest, maybe the higher-ups in Border know something.” 

Osamu looked at Jin for a moment before raising his hand, “Um, Jin-san, did you foresee the moon getting destroyed from your side effect?” 

Jin seems to think about his answer before answering Osamu’s question, “Well, it was one of the possibilities, but I didn’t think it would actually happen” 

Yuma squints at Jin’s answer but doesn’t say anything about it. Everyone was satisfied with this answer and went to bed, except for Yuma, who went back to the roof to look at the moon. 

 

“You make the funniest lies, Jin-san……”

 

~line break~

 

A few weeks after the moon incident, the students in E-class were just thinking that it was gonna be another usual school day, rude teachers, bullying, hateful behaviour from the other classes. Still, they definitely didn’t expect to see a weird-looking octopus(?) come into their class.

 “I’m the one who blew up the moon. However, I will be your teacher from now on.” 

.

.

.

“HUH?!”

 

Karasuma’s POV

It’s been about a month into operation Assassination Classroom, a lot of things have happened, the students receiving their mission, new students and teachers joining the class, and field trips. However, now I seem to have something else to worry about. 

“A letter of request from Mikado City’s Border Agency…..they want to send 2 of their agents here to assist us…..” 

Border isn’t as well-known outside of Mikado City; however, they are strong enough to know about an international secret. 

“Hmmm…from what I heard, Border seems to deal with supernatural beings, and it's basically a military base to train people to kill aliens… maybe this can be a great asset for the class…” 

 

Yuma’s POV

“Huh? Me and Jin? To a school? For assassination?”

“Not just for assassination, Yuma.” Commander Kido sighs while putting his hand on his head. 

“This is top secret to the outside world, and I believe that this can benefit both sides. I hope you two are up for the job.”

I looked over to Jin, who seemed calm and composed as always.

“Figured you were gonna ask us about this, thanks to my side effect, of course. Anyway, I’ll let Yuma make the decision here.” 

I put on my usual duck face while thinking about it. 

“So?”

.

.

.

“Ok, got it, we’ll take the job”

 

Nagisa’s POV

“Hey, did you hear? I heard that we’re getting a new student AND teacher today. Do you think they're assassins?” 

“I mean, since they're coming in this class, they must be helping us with the assassination, right?” 

“I heard that they're both boys and that they're older than us by a bit.” 

I overheard my classmates talking about the new student and teacher who’s coming in today, but it is kinda strange, we’re about a month and a half into this, but people are still joining in? I wonder what kind of person they will be…… 

 

“Everyone, settle down please.” Koro-sensei and Karasuma-sensei walked in, and we all went back to our desks. 

“As some of you have heard, there will be new additions in the class today. They are here for a few reasons, but they’re mostly here to help us with the assassination.” 

Kayano raises her hand to ask a question. “So are they assassins then?” 

Karasuma thought about the question for a bit, “Well, in a way, I suppose, they work for an agency in Mikado City, which you may or may not know about. I’ll let them in now to explain it more to you guys.” 

Karasuma-sensei went out to get the new student and teacher in 

“Ahhh, I can’t believe we’re getting a new student and teacher this time, but it sure is nice to have new faces in the class, right?” Koro-sensei says in excitement. 

 

“Excuse us.” An unknown voice was heard as two new faces entered the room. 

The one that stood out to me was the short boy with white hair. Is he an elementary student? The other was a tall guy with brown hair wearing some weird-looking glasses.

“I’m Yuma, Kuga Yuma, and I know I don’t look like it, but I’m 15 years old. I'm just really short. The person beside me is Jin Yuuchi. We’ll be assisting you with your mission from today onwards.”

 I see the class staring at them; they're definitely unique…..in a way.

“These 2 are agents from the Border Agency in Mikado City; Jin is an A-rank agent, and Yuma is a B-rank agent,” Karasuma stated. 

I can see most people looking confused, but some look shocked. 

“Wait, wait, wait, Border!?” Maehara stood up while shouting, “Isn’t that the agency that deals with those alien things that's in the city???” 

The guy called Yuma nodded at what Maehara said: “Yes, that Border, we’re sent here due to a request from the higher-ups for several reasons.” 

“First, to assist you in eliminating the target. Second, to do some experiments on whether a neighbour's weapon can deal damage to the target. Lastly, to introduce you guys to Border.” I paused. 

Huh? Why do they want to introduce their agency to us, and what even is Border and Neighbours? I raised my hand, 

“Um, excuse me, but why do you want to introduce Border to us?” I asked in curiosity. 

“Well, that's simple, we want to promote Border more to people outside of Mikado City and also because we see potential in this class that you guys can become elite agents. If any of you are interested, Border is open for talented and capable individuals.”  

The guy beside Yuma, I believe he’s called Jin, said excitedly, 

“Anyway, from now on, I am a teacher in this class, teaching you a bit on fighting and also about the Border Agency. Yuma here will be a student who will also be assisting me in teaching.” He said while ruffling Yuma’s hair. 

 

Well……this certainly is unexpected….

 

Jin’s POV

While Yuma was explaining, I took a look at the students in the class; some stood out like a red hair delinquent looking guy at the back of the class. I believe he’s called Akabane Karma. From what I read, this guy is quite skilled in fighting, and he’s also the first student to deal some damage to the octopus. 

There’s also the girl…? No, never mind, that’s a guy, Shiota Nagisa. He doesn’t look like much, but from the reports I received from Karasuma-san, he’s probably the most skilled at assassination and stealth, and it also seems like he has a talent for reading people’s emotions….Either he’s really observant, or…something else is at work…perhaps a side effect? 

Oh well, this is certainly an interesting class. 

Karasuma-san stepped in to further brief the class, “As Jin said, he will be teaching you about Border, combat, and more. Yuma will join you guys as a student who will also assist in teaching.” 

A student with orange hair raised his hand, “Wait, but Karasuma-sensei, aren’t you teaching us combat now? Will Jin-sensei join you in teaching us?” 

“Ah, well, you see, I will actually mainly be teaching you about trigger combat,” I said knowingly. I did get a lot of questioning looks, but no matter, I’ve foresaw this long ago. 

“Don’t worry too much about it, I’ll teach you more about it!” 

“Nurufufufu….glad to see more teachers here. If you need any help, I’ll be happy to help you, Jin!” The octopus- no, I mean, Koro-sensei, reached his hand? Er…tentacles to me to shake. I reached my hand out to shake his. 

“Glad to be working with you, Koro-sensei!” I said with a smile. 

I see Yuma’s small figure do a bow to him and the rest of the class. “I hope we’ll get along now, classmates.” He said with his usual duck face. 

The class is filled with warm welcomes and friendliness. I was glad the class was welcoming him. It’s nice for him to make more friends with people outside of Border. 

 

“Anyways! Now that we've got our introductions done, I just got a question for you, Koro-sensei.” I turned to him. 

“Oh? What question do you have for me? Is it about my speed? My dashing looks? Or my handsome face!” I can sense the class facepalming at his reply. 

“Well, it’s nothing much, but I just need to confirm. Are you a neighbour, Koro-sensei?” I waited for his reply while looking at Yuma for his signal. 

Koro-sensei stared at us for a second before he started doing his weird laugh. “Nurufufufu…interesting…Well, the good news for you is that I’m not a neighbour! I am very much a human on the inside!” He said as it raises his tentacles in the air in triumph. 

I waited for Yuma to do his thing, and he nodded his head. I smirked. “Well, great! Nice working with you then, Sensei!” I patted him on his back. 

 

At least we have confirmed that he is not a neighbour.

 

“Well then, since introductions are over, why don’t we sit down now?” I smiled at the class. This will be an eventful class to teach. As my side effect told me. 

 

Yuma’s POV

Once Jin-san confirmed that Koro-sensei is not a neighbour, he seemed to feel relieved. He definitely knew that he wasn’t a neighbour, but maybe he just wanted to confirm it. 

Karasuma-sensei directed me to my seat, and I went to sit down before being swarmed by my new classmates.

“You work for Border? How is it like working there?” An orange-haired guy eagerly asked me, he reminds me of that one guy who was a big Border fan back in Mikado City. 

“Yeah, I do, I kill neighbours and train, nothing much,” I replied. 

“Why is your hair white?” A short girl with green hair asked. 

“It was originally black, but it just turned white one day”, I put on my usual duck face as I continued to answer their burning questions. 

“Wow, you're really short! You're even shorter than Nagisa-chan!” A red-haired guy sneered at me. 

I saw a blue-haired androgynous guy proceed to knock him on the head. That guy must be the “Nagisa-chan” he was talking about. 

“Being short has its advantages.” 

 

….I guess Jin-san was right when he said I’ll be enjoying this mission.

Notes:

Karma: "Why are you so short"

Yuma: "'Cause I stopped growing"

Karma: "Yeah, that's obvious, but why"

Yuma: "'Cause I died when I was 11"

Karma: "Oh yeah, makes sense..........WAIT WHAT-"