The Assassination Classroom is real?! (Various x reader)

I meet Itona!

I woke up with my body sore as heck!

"Ugh what the heck" I rubbed my arms as I looked at the time. '11:30!?' "DAMN KARASUMA!" He didn't wake me up!!!

I looked at the clock again when I noticed a letter from him. I grabbed it and read it:
'Dear {y/n},
I decided to let you sleep in because you need a full 12 hours for your body to fully absorb the drug and since we gave it to you so late i decided to keep you home. I left you my credit card just Incase you wanna explore more of the town but just be careful. Call me if anything.
-love onii-Chan-

I smiled and later back down. "That was sweet of him!" I smiled and sat up. "Let's not waste the day in bed, let's see what this town gotta offer"

I ran out and took a shower, changing into a skirt with leggings and a off the shoulder shirt. I grabbed his card and small purse and left.

I walked into the more busy area and looked around. I got weird looks, knowing that I'm a foreigner, I don't care really. I then saw the cutest pair of shoes that could help me hide some weapons against sensei!!

I went inside and looked for my size Great!!

"Excuse me do you have this in a size 6?" I asked the lady. She seem shocked for my Japanese.
"Yes I'll bring it to you right away" she takes it and bows slightly and leave
"I will never get over how they bow all the time" I shrug and sit down and look at my phone

After a few minutes she came back with 2 boxes?
"I found that we have them in black and a light baby blue I don't know which you like so I got both" she sets them down
"Ohh! Blue! I'll take the blue ones!" She nods and we walk the register.

I buy them and go to the park. I walk around and observe the area.

"This is nice, families running around and people with pets, it reminds me back at home.."

I started to feel sad thinking about home, aw man I missed it. I sighed "Damn it" I then heard a giant bang.

"What the hell?!" I look to see a white haired kid starring at a trashcan with a giant hole in it.
Could it be???
"I prove to be stronger than the trashcan" he said
"No way..Itona?!" I said and he turned to me and his eyes went wide.

He's so obsessed with power...he's gonna have to try and fight me.

I sighed and walked towards him and he froze.

"What's wrong Itona?" A man in all white walked next to him.

It's him.... that bastard!!

I can feel my anger boil with every step that I take when I get closer; and he finally looked up at me and when we locked eyes I allowed my eyes to change to red. I wasn't going to hold in my anger for him!

They both took a step back.

"No way...she..." Itona couldn't even speak because he finally felt fear in the first time in his life.

Once I was only a few feet away I finally spoke.

"You...Shiro-sensei..." I growled at him
"Your so lucky I don't kill you right here and now...." I clenched my fist
"Y-You? Kill me? Ha you wish little girl" he stuttered but quickly regained himself.
"If I did it'll mess up everything and I don't want that to happen..." I continued to glare at him.
"I need to leave if I stay here any longer I just might kill you" I took a step away with out breaking eye contact.

Just then Itona broke out of his gaze and took a step towards me. But Shiro-sensei put a hand on his shoulder. "No Itona this match you won't win"  Itona looked shock and looked at him in a pleading matter but all he did was shake his head.