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He hadn’t expected to become attached. He’d promised to teach them, to guide them, and that’s what he intended to do. Logically, he knew he’d become fond of them, he’d already been half-way there after hearing about them. He hadn’t anticipated that he’d come to view them as family, that he’d come to view him as family.
*-* *-* *-*
He remembered the grenade, he was sure his students did too. Nagisa had impressed and terrified him in equal measure, something which very few others had managed before him. But the boy was a child, a child who hadn’t been exposed to the world of assassination for long.
He hadn’t thought twice before reaching out to stroke the boy’s head. He remembers the flinch, but he also remembers the way he’d leaned into it. He didn’t know Nagisa’s situation yet, but he at least had some idea of how to help.
*-* *-* *-*
It hadn’t surprised him when Nagisa started to make note of his weaknesses, it was the logical thing to do in their situation after all. At one time he may have been wary of someone documenting such a thing, but then and now were different; he just had to hope he made the right choices this time.
He’d ruffled the boy’s hair again just as he was walking out the door at the end of the day. He didn’t flinch that time, something which Korosensei decided to mark as a win.
*-* *-* *-*
The affection he held towards the boy gradually increased over time, as did the way he expressed it. Head pats shifting into one-armed – one-tentacled? – hugs. He didn’t change the way he addressed him, but he couldn’t quite hide the fondness when he did.
*-* *-* *-*
Korosensei could tell there was something wrong when he saw Nagisa slumped over his desk, the others hadn’t arrived yet, something which struck him as being rather odd. The boy was usually one of the first to arrive, but never this early.
“Nagisa?” The boy roused slowly, blinking up at him while he regained awareness. He looked like he hadn’t slept for a while.
“Korosensei?” Nagisa sat up, trembling slightly. He merely reached out a tentacle to wrap around the boy’s shoulders.
“I’m here.” He commented before gently nudging his student to his feet. “Come on, I doubt it’s comfortable sleeping at a desk.” He wrapped a few more tentacles around the boy to keep him steady while they walked, he would’ve just picked him up but he wasn’t sure whether he’d be okay with that.
Karasuma was already in the faculty lounge when they got there but he didn’t seem inclined to start a conversation, he rarely did. Korosensei paid him no mind while he guided his student to the old couch wedged against one of the walls, prompting him to lie down while he retrieve a blanket and pillow.
“Get some rest.” He instructed, making sure the boy was properly covered. “Come back to class when you’re ready.” Classes hadn’t actually started yet but he’d copy down a few notes for the boy anyway.
*-* *-* *-*
Nagisa’s mother was…something. He’d come across many people during his time as an assassin, and while he wouldn’t consider her to be on the same level as some of them, knowing that this is who his precious student has to return to at the end of each day…it wasn’t something he’d ever wanted to think about.
He remembers the way she’d yelled at his student, remembers the fire. This was wrong. The way she treated him was wrong.
Nagisa didn’t go back with her.
*-* *-* *-*
Things became easier after that. Korosensei wasn’t sure whether or not he should be concerned about that, but the boy…his boy seemed happy, he wasn’t about to ruin that.
*-* *-* *-*
It became second nature to sneak sweet treats into Nagisa’s bag while the class were training with Karasuma. His boy never made a big deal out of it; he wondered if maybe it was too much? He almost wept when he saw a small pile of desserts hidden beneath his desk, the small doodle of a snake was all he needed.
*-* *-* *-*
One day after class he remembered the trip to Hawaii, remembered how happy Nagisa had been. He wondered if there was anywhere his boy wanted to go.
The trips didn’t happen as often as his solo ones. Even now, Nagisa was still hesitant to ask for things that might inconvenience the other person, and he didn’t want to risk making his classmates jealous.
He solved this problem by taking the class on an impromptu trip to the beach…in America. Karasuma hadn’t been happy but the students had enjoyed themselves so he decided to count it as a win. Nagisa still didn’t ask to go on trips, but he was far less hesitant about accepting offers, especially if some of his friends were invited too.
He probably went overboard on the souvenirs but Nagisa didn’t seem to mind, it was nice seeing the way he smiled when he tried to figure out what to get for the others.
Why anyone would want to hurt this boy was a mystery Korosensei didn’t think he wanted an answer to. There wasn’t anything that could justify it.
*-* *-* *-*
“Thanks Dad.” Nagisa froze, he froze, the entire class froze. No one moved for a few minutes. Nagis bowed his head, burying his face in his hands. That wouldn’t do.
“You’re welcome, my boy.” He reached out a tentacle to playfully ruffle his hair, chuckling softly when he leaned into it.
“Holy shit.”
“Language.” He reprimanded softly, watching as the surprised atmosphere morphed into one of amusement. Well, he supposed it was to be expected that they’d find out eventually.
*-* *-* *-*
Playing games with the class at break and lunch had always been fun, something which the reveal only seemed to enhance.
“Team game, father vs. son, sound good?” Well, it would certainly be interesting Korosensei thought to himself with a chuckle. He lost.
He couldn’t bring himself to be upset though. Not when his boy was having fun, not when he was laughing so freely.
*-* *-* *-*
Stargazing became a habit they both enjoyed, the isolated nature of the mountain making it easier to see them. It was peaceful at night…when the occasional assassin wasn’t trying to take pot shots at him anyway.
“I’m proud of you.” He murmured to the sleeping child cradled in his tentacles. He knew his boy wouldn’t hear him but it didn’t matter, he’d just tell him again when he woke up.