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No strings- My Fault rough draft

Unfortunately, Karasuma isn't the only teacher that has an office here.

The octopus approaches me with that obnoxious grin on his face. Ever the opportunist, I hide my knife up my sleeve and decide to wait until he's distracted. If I can get close enough I might even get a clear shot at his head.
"Hey Karma? Mind if I join you."

"Fine, Not like anything I say matters, I know you'll do it anyway."

"That's not necessarily true, your my student! It's my duty to respect your boundaries!"

I sent him a pointed glare and he shuts up. He knows that minding his own business is his weakness, which seems to work in my favor.
He sits next to me, trying to mimic my pose, which looks incredibly forced and exceptionally odd considering that he is indeed a killer octopus and not a human being.

"So, karma, what's got you looking so blue?"

I hesitate. Should I tell him? In any other circumstance I would dismiss it as nothing, but this time it's not me, it's nagisa. I know he needs help. I know he's in danger and I don't think I can save him on my own. An killer octopus that can move at Mach 20 might be a helpful ally. At the very least korosensei would be able to spy on the house without being caught. He might actually be able to help... but can I really trust him?
God I hope so.
"I think my friend might be in trouble. He's really starting to worry me."
His aura shifts to a calmer, more friendly demeanor. He sports the familiar maniacal grin, but something about him seems more gentle. I think this his best attempt at offering comfort. It's not really working.
"Oh dear, it sounds like this friend of yours might need some help. Can you tell me more about the situation?"
And this is where I freeze up. Why didn't I think about this? Nagisa would be so pissed if he ever found out I told anyone, which is exactly why I'm telling no one. Maybe it's not to late to backtrack here... it's worth a shot at least. 
"I... I don't know if I want to talk about this with you. It's not my secret to share. He would hate me for the rest of his life if you did something and he found out I was the one that told you."

This seems to be enough to shift the topic enough to steer away from Nagisa's home life, as korosensei gets all flustered trying to defend himself.

"What?! Me?  Do something?! I would never! Unless your friend is in danger, but wouldn't you rather he live and be angry than live with the guilt of knowing you could have done something and didn't?"

"Yeah, obviously... and I'm going to do something about it. It's just complicated."

And for some reason those words hit harder than they should. It's not like it's the first time it's crossed my mind that Nagisa could end up dead. It's not. I've known this. I've been actively working towards changing that outcome, but the knowledge that his mom could snap at any moment and decide she just doesn't want him anymore, or the he could cut too deep with no one around to save him, or end up passing out in the middle of the road again, or... I think you get the gist. It's not the first time its come to mind. The thought of nagisa dying because I failed to save him plagues my every waking moment. So it's not korosensei's life or death ultimatum that scares me. It's the fact that someone else is recognizing it too. I've always been the only one to pick up on it. I've told my parents they don't listen. Ive tried to tell teachers, which just makes it worse. Hell I've even called the police a few times just to be ignored. No one has ever taken this seriously.

"Look, I know that you're my teacher and all and I'm supposed to trust you or whatever but I'd really rather talk to Karasuma on this one"
Korosensei gives the closest thing he can offer to sympathy by patting my head with one of his tentacles.
"Sorry kiddo, Karasuma is out on official detective business today. He said it was super important and from what he told me I'm inclined to agree."