Rindo was back to his normal life.

And it was bizarre; everyone around him acted like nothing terrible had happened just a week ago. Literally, all of Shibuya had been warped into mindless zombies, and then the city basically imploded! And if it weren't for him imitating Marty McFly, no semblance of this current lifestyle would even exist.

Instead, guys are talking about the latest challenge on TikTok where you're supposed to stack milk crates and try to balance on top of them. Lame? Girls are gossiping about hot boys, as per usual, and …

"Did you see our new math teacher?" A nearby girl giggled to her friend, far too loudly in the hallway— swear to god, Rindo wasn't trying to eavesdrop—

"No, why?"

"He is soooooo dreamy!"

Huh. Didn't think they'd get a new teacher this year, but okay. Rindo pulled his mask over his face, whipping his phone out to text his buddy about the news—

"Heeeeey, Rindude!"

… Never mind. Fret's got his arm around him now. Rindo pulled his mask back down.

"Fret, did you hear we have a new math teacher?"

"Noooooo. I mean, should I have? I guess, huh? I never get any email updates about this kinda stuff!"

Maybe he should try reading the corkboard full of school announcements…

… who is he kidding, nobody reads that thing.

"You think they're gonna be a hardass?" Fret pushed his wavy locks out of his eyes, ruminating over this new development.

"No clue. But the girls over there," he vaguely gestured to where those thirsty teens stood, "were talking about how hot he was."

"... Well, I guess if all else fails, we'll be graced by his beauty, riiiiight?"

Rindo said nothing for a moment, only turning away from his friend. Cocoa eyes grew dull. Sigh. A leap into the unknown was always a risk. But if he could handle the last three weeks, he knew this was a cakewalk in comparison.

It'll be fine.

"Right…"


Rindo took a seat at his desk, next to his BFF, ready to learn (not really). It just so happened to be that the first class of the day was math, so—

"R-Rindude…!"

"What?"

Fret yanked Rindo's arm, nearly toppling the blonde out of his seat. And he would've hissed at his best friend for not respecting boundaries, but—

"Is that— is that Mr. Minami?"

Rindo followed the direction that Fret was pointing to, and indeed, there was a pair of glowing, yellow cat eyes within the door's corridor.

"Huh…?"

In comes a familiar face, donning lace-up boots and a majestic black trench coat with a hood, concealing his face in hard shadows. He bore shiny white fangs with his twisted grin — or what appears to be a grin? — and then pressed a megaphone to his face —

"Listen up, zeptograms! You're here today to solve some equations! And if you miscalculate, you'll end up crunched, got it?"

As if to prove his point, the mathematician slammed his fist into his palm.

Oh…

Oh GOD.

Rindo looked to his buddy, who appeared to be smiling in joy and yet… crying at the same time. And he knew why. Mr. Minami may have been their savior in the UG, and he certainly knows his stuff… but…

… Nothing he said ever made sense!

How did he even get here?

And how did he get away with that outfit? That's not school appropriate!

"We're gonna fail this class, aren't we?" Fret's tears stained the desk beneath him.

"... Yeah."

"You there, Y-intercepting derivatives! Turn your volume down to zero or you're getting a zero!"

Rindo's ears popped from the megaphone — did it have to be like, 3 feet away from his face? Why did Mr. Minami walk all the way over there to shout at them?

10 minutes into Mr. Minamimoto's class, and he's spouted on and on about inverse matrices and also recited the first 150 digits of pi, and nobody is quite sure what the hell he's going on about. Now, he's just standing there writing down a gigantic proof on the chalkboard. Whatever… whatever that means. This was far too advanced for… geometry…? Was it even geometry? He's like, trying to prove that a triangle is a triangle.

"Can't you just look at it and know that it's a triangle?" Fret whispered. Sho's chalk then snapped in half.

"Eep…!"

. . .

The air was palpable, and although Minamimoto continued to stare at the chalkboard, Fret could feel his icy glare reach him through the back of his head somehow.

A long pause before he then reached for another chalk, and continued writing…

"Phew."

Assuming that is a right prism, we have that CC' is perpendicular to the triangle ABC and since this is …

Fret rocked back and forth in his seat.

by the Pythagoras Theorem, the diagonal of this rectangle, B'C = √ (BB')² + (BC)²

. . .

"Now we're gonna prove triangular numbers by induction—!" the new teacher yelled, slamming his hands together to rid of the white powder…

… Only to grab another new piece of chalk, because he already burnt through the other one!

One proof of triangular numbers is by induction.

T(n) = 1 + 2 + 3 + ...+ n = [n ( n+ 1)]/ 2

Proof: Let n = 1.

If n = 1, then [1 (2)] / 2 = 1, which is true.

Let n = k such that k is a positive integer—

Minamimoto was ripping through the chalk faster than the school could ever replenish them. And Rindo could not take much more of this. Did anyone else feel the same?

A quick glance behind him revealed that girls were simply drooling at the mathematical beast, and the boys were just playing on their phones.

Regardless! It had to be corrected, lest he gets a bad grade and gets grounded! He's gone through worse! He can do this!

His hand slowly raised…

"M-Mr. Minami, sir…"

A girl whispers in the back, "How did he know his name…?"

And Minamimoto whips around, annoyed features half-concealed by the shadow of his hoodie.

"What do you want, masked zeptogram?"

"Aren't we supposed to be like, creating lines? And stuff? You know, geometry?"

Basic geometry, to be precise.

Sho's fangs gleamed once more, and he all but started snarling at the children.

"Tch! Like I give a digit about what you think you're supposed to be learning, you hollow-skulled hectopascal. The pre-approved curriculum is zetta garbage! Subexponential complexity! To plot the points, you've got to know at least a picogram about why the coordinates even exist. You tasteless tetrahedra don't deserve math—"

Oh, no. He's going on and on and on and on with such overzealous passion; some of the girls found it hot — "I loooooove smart guys!" — and most of the boys just found it terrifying, including Fret. And then there's Rindo, gulping with every word that Minamimoto spat out, Googling furiously on his phone—

"Sub... exponential... an algorithm whose running time as a function of the size x of its input grows more slowly than b to the power of x for every— what?"

He still doesn't get it.

"Hmph. If all of you undistributed trinomials aren't going to give a fractal, then my remaining time here equals zero. QED! Class is dismissed!"

Out he goes with a magnificent flourish of his trench coat.

Wait, he came back in to grab his megaphone off the desk.

NOW he's going.

"W-wait, Mr. Minami!" Rindo cried out.

Deafening silence remained in the classroom, except for the one nerd who had moved up closer to scribble all of Sho's notes in his notebook with maximum fervor.

"Awwww, Rindude. We're so screwed…"