I do not own BNHA or any of its characters.

A short drabble inspired by a post by alicekaninchenbau on tumblr. An AU in which "All Might" was not hired to teach at U.A. but instead Toshinori Yagi teaches Foundational Hero Studies and no one but Principal Nedzu, Recovery Girl, and Izuku know he is All Might.

Izuku perked up at the sound of the large door sliding open.

From the hall strode in a tall, sickly-skinny man in a surprisingly bright yellow suit. Murmurs broke out around Izuku.

"Who-?" "Is he a teacher?" "His hair is so wild. Even worse than Aisawa-sensei's." "He looks sick. Is he really okay?" "I thought all teachers in the hero department were heroes. Do you recognize him?" "No?"

But Izuku smiled in delight at the familiar man. "All M-"

"ALRIGHT!" All Might exclaimed suddenly, flashing a nervous grin to the class and glancing at Izuku, "Take your seats, please. We will begin momentarily. Ah, but first. Midoriya, young man, will you come out into the hall a moment?"

Some of Izuku's classmates glanced at him curiously as he stuttered "yes" and hurried to follow his teacher and predecessor into the hall.

All Might shut the door, glancing up and down the hall before sighing, his shoulders slumping in exhaustion and relief.

"Midoriya, my boy, I wish I could have warned you sooner but circumstances did not allow." All Might explained in low, hushed tones. "Here, in this school, no one but yourself and two others know I am All Might."

Izuku's eyes widened in surprise, "R-really? No one else knows you're-"

"Yes. At U.A. I am a teacher and a 'former hero.' At least, that is the official story. I can't properly teach as the hero All Might if I can only perform as a hero three hours a day. So to both teach and maintain the secret of my condition," All Might gestured at his emaciated form, "I have to keep this cover. Understand?"

"Oh!" Izuku covered his mouth. He'd almost blown All Might's secret with a careless greeting, "I'm sorry! Yes, I understand!"

"Don't worry," All Might chuckled and threw up a thumbs up, "You know now. Here, I am just Toshinori Yagi. Yagi-sensei for you and your classmates. Okay?"

"Yes, All Might, ah, Y-Yagi-sensei," Izuku stuttered the unfamiliar surname and nodded.

"That's my boy," Toshinori said with a lopsided grin. He made as if to open the classroom door before he turned to Izuku again, "Ah, and if anyone asks why I called you out - I was your tutor over the summer and we were just briefly catching up. That will allow us to talk and train in private without unnecessary questions. Is that alright with you?"

Izuku nodded seriously, mentally noting to memorize the cover story, "Yes, Yagi-sensei."

Toshinori chuckled and ruffled the boy's hair until he smiled bashfully.

"All right. Time for class," Toshinori slid the classroom door open, allowing Izuku to enter first and return to his seat while Toshinori walked across to the podium.

"Foundational Hero Studies!" Toshinori exclaimed with a grin and a hacking cough. When he recovered, he continued, "I'll be your instructor, Toshinori Yagi. For this class, we'll be building up your hero foundation through various trails. Let's jump right in with this," he lifted a card from the podium. On it was a single word: BATTLE. "The Trail of Battle."

A short and sweet drabble written at 3am.