Infiltration was not a mission type Gekkō Keisuke was designed for.

Didn't mean she didn't have the skillset for it, no matter how she'd reached that point. Despite a Gordian knot of coincidences and at least one soul-based mishap, she was still left with a strong Nature Release specialty, immense endurance from being a jinchūriki, something of a multicultural education, and the ability to read, speak, and write English. Between the limited preparation time and the possible threat level faced by any shinobi who attempted this mission, there were only so many candidates even before dimensional travel was factored into the Hokage's decision.

Which was why she was chosen for a very special mission to infiltrate a Japanese high school.

Hey, Isobu.

Yes?

Riddle me this: How am I, a freaking special jōnin, supposed to answer this question?

Kei, it had to be said, had not needed to compose an essay for anything in Japanese since her successful Chūnin Exam. Mission reports? Sure. Fūinjutsu write-ups? Part of the job. Proposals regarding usage of village resources for local and national problems? It cropped up on occasion, but not consistently.

Isobu's mind peeked over her figurative shoulder.

American high schools only required students to register or be registered for coursework by their parents, as far as Kei recalled. Her actual high school years were a little vague by this point, having devolved into hallway-shaped blurs punctuated primarily by friends and trivia. Mostly friends. In Konoha, compulsory education for shinobi was less of a formal affair and more on-the-job training a thousand times over, leaving holes all over the board.

And unfortunately for Kei, Japanese, mathematics, science, social studies, and English were all required topics. Kei's Japanese was better than some of her peers, given the emphasis her skillset placed on calligraphy and kanji, but social studies was a wash. Japanese was probably not much better, and it was followed down the drain by mathematics. Science was middling, given the problems imposed by slamming into an alternate universe with ubiquitous internet when the shinobi-ruled world barely understood radios.

But dammit, Kei at least knew some things. Even if her English was informal, she'd done her time in the appropriate school system. Time to get some use out of it.

It was just a matter of muddling along until she could get to the practical.

Why couldn't a friggin' hero academy of a high school just involve knocking muggers unconscious? Kei knew how to do that . Without killing anyone, even!

You were supposed to change the exponent too, said Isobu, who read the questions through Kei's eyes.

Dammit, Kei thought, and erased her second equation. She cracked her knuckles and drew glares from the students around her, but ignored them. At least it's not differentials. Always sucked at those.

…You know, seeing you attempt calculus at this stage would be hilarious.

Thanks a bunch , Kei told him, and got back to work.

The math test came and went. The social studies test followed suit, reminding Kei that her "peers" were working with a solid decade of education and cultural context she didn't have. Even if she'd been truly Japanese, there was a real chance a child from her version of Japan would have failed the entire section on Quirk legislation. She probably didn't fail science, between Isobu and Kei's discussion method and what she could extrapolate from the briefings regarding Quirks. And English? There was something of an edge there, and Kei and her Tailed Beast buddy had ever been a pair fond of using everything at their disposal to win.

And then, the dreaded practical exam.

With Isobu acting as her live-in Jiminy Cricket, in the exact opposite way a conscience was generally supposed to work, Kei managed to tune out the DJ-like announcer for the practical examination on the big day. She had her paperwork in front of her, a mission prodding at the back of her head, and a whole room full of hero-hopefuls who were probably going to hate her in about fifteen minutes. She did listen to enough of the explanation to know how the robot targets were going to be scored, and could see some figures in the crowd start to slump for one reason or another, but ultimately the information felt extraneous.

Kei had no intention of allowing a written exam keep her from completing her mission. To that end, she would happily destroy every opponent in the examination stadium with only Water ninjutsu. It was a nice way of working off stress.

Kei filed out of the room alongside the other potential students when the intro spiel was over, taking in the crowd. She could see a wide variety of body types, features, and open fear among the examinees. Assuming any of them got in, she'd try memorizing names and faces then.

Her mission would take priority.

"You need to have a paper trail." Sensei's frown had been audible over the connection, probably because he had no experience with cell phones and a lot of experience with genjutsu. Not a Luddite, but really unfamiliar with tech.

"That won't be a problem. We'll just have her take the entrance examination along with all the other heroes-to-be." The Mickey Mouse soundalike had given her chills, at least up until she'd realized that they actually were speaking to a talking mouse. Sensei probably would have called him a summon, but Nezu assured them that Quirks worked in mysterious ways. And he actually was a mouse. Probably.

Maybe?

"If it's what the client wants…" Sensei's chakra signature remained wary, but it hadn't shown in his voice. "One academic year or until the threat is ended, whichever is shorter."

Sort of like any warranty, really. Kind of funny, in hindsight.

"By your command, Hokage-sama."

And here Kei was, dressed in gym clothes for a school she'd never attended and waiting for the hammer to drop. She tapped her shoes on the ground idly, getting used to wearing something other than sandals for the first time in nearly a lifetime, just to feel a bit more prepared. The exam robots were just there for racking up combat scores on opponents who didn't bleed. Some of the kids around her would be able to go all out. It'd be fun.

But apparently not for the kid just to her left, who looked like someone told him life was cancelled. He had his arms crossed and eyed the entrance like it was a gallows, not a set of unusually large double doors. Another kid looked like she was going to throw up from sheer nerves. Two boys were stretching, while a girl near the front of the crowd was nearly bouncing in place.

Welp. Time to ruin their days. Probably.

"GO!" screamed the digitized voice of the cockatoo-headed announcer, and Kei went to work.