

A high school senior finds his homeroom teacher obsessed with grooming him into a perfect sexual instrument, their risky encounters escalating as Izuku secretly calls the man "Kacchan." Mr. Bakugo is determined to train Izuku's virgin body solely for his own massive cock, blurring every line between student and teacher.
Start things slowly. Katsuki has started to notice the boy he’s been obsessed with has been staring at him a lot during class. So Katsuki asks Izuku to stay late and starts by acting like a normal teacher. Asking Izuku what is wrong, what’s been bothering him lately. It takes some coaxing, but he gets out that Izuku has been getting wet and he has no idea what that means. He thinks something is wrong with him. Katsuki realizes Izuku is getting sexually turned on by him, but poor Izuku knows absolutely nothing about sex. Not a single thing. Izuku even uses childish words for genitalia like kitty for pussy and willy for cock. Izuku still has the innocence of someone much younger.
A few days later. Katsuki watches Izuku closely, but waits for the boy to come to him after class. Izuku has questions about boys willy’s. He’s never seen one before and he’s curious. Katsuki is willing to teach him. Katsuki shows off his massive willy, soft at first. Izuku watches it get hard and Katsuki touches himself in front of the boy. He tells him all about the different parts of his willy and shows off his big full balls. Especially showing off his uncut tip. Explaining how most willy’s don’t have this “hood”.
Izuku eagerly asks for his third lesson a couple days later. Katsuki starts be explaining oral sex. Explaining a blow job is great detail. Katsuki pulls out his huge horse cock and guides Izuku in touching it. Then when it’s throbbing hard, he guides him in tasting his precum. Running his little tongue down his length to his balls. He guides him in sucking at his balls. Saving his cock for last.
A few days later. The command landed in Izuku’s gut, hot and heavy. His own untouched need, a throbbing ache between his legs, suddenly became the entire world. The tile was cold through his uniform pants as he shifted, but the heat radiating from his own core was a shameful, undeniable truth. Katsuki’s gaze was a physical weight, pinning him in place, demanding he prove his body’s training went deeper than his throat. Katsuki lays him out on a mat, spreading that pussy and eating him out. Izuku turn to moan and talk about how much he loves Kacchan’s mouth, these special lessons, how much he loves his Kacchan. Katsuki eats and sucks at his pussy until Izuku has squirted multiple times and overstimulated.
The bedroom was stark, dominated by a large bed. Izuku's back hit the cool cotton, and the scent of Katsuki—clean, sharp, male—enveloped him completely. This was the inner sanctum, where the teacher vanished and only the predator remained. When Katsuki's weight settled over him, the world shrank to the size of this mattress, this claim. Izuku understood: here, his training would be completed, and his old self would be erased forever.