Nezu walked into the room labeled "friends" and closed the door locking it

????: hey your back

Said a creature the same size as Nezu

Nezu: I am, and I have good news. I found Cosmo

????: r-really? Where is she, is she hurt?

Nezu: calm down Rocket, she's fine

Rocket: she better be...

Nezu: it's fine, she's with a student here, he is taking great care of her... she's enrolled as well as a student

Rocket: heh... animals as students..

Nezu: well, I'm an animal, and a hero... technically

Rocket: hehe... well then, now what?

Nezu: do you... want an offer Rocket?

Rocket's ear twitched as he looked at Nezu with a curious face

Elsewhere and a bit further in the future

Kinoko: universal studios Japan?

Aizawa: no, *groan* the Unforeseen Simulation Joint. This is the place we'll be going today, here you students will be training some more, so make sure your ready for anything we throw at you

Izuku: I am Groot

Rikido: I agree, it does sound fun!

Bakugo: wait, you understand him?

Rikido: yeah, it just kinda... grew on me I guess... the more your with him the better you understand him?

Izuku: I am Groot...

Rikido: you believe my theory? Thanks Midoriya

Aizawa: Shut up, get dressed in your hero suits and meet me at the bus in 15 minutes

Aizawa got in his cocoon of a sleeping bag and rolled out of the room

Izuku just simply grabbed his case, put the weapons he had for support gear back inside him, and walked to Aizawa

Izuku waited at the bus while everyone else got suited up

Cosmo: hi master!

Cosmo said as she jumped onto Izuku

Izuku chuckled as he pet her head

Izuku: I am Groot

Aizawa: so, climb aboard the bus, don't dawdle

As the class got onto the bus... one thing stood out

Izuku: I am Groot?

Kinoko: I don't know-

Rocket: who the hell are you calling a raccoon?

Izuku: I am Groot

Rocket: well I'm not a raccoon!

Aizawa: he will be joining us for our training... Nezu's orders

Cosmo: *gasp* Rocket!

Rocket: Cosmo? COSMO!

Rocket basically jumped and hugged Cosmo

Cosmo: are you ok? Last I saw you-

Rocket: I know, I know. Are you ok?

Aizawa had already started the bus but that didn't mean he wasn't listening in to the conversation... well. Half of it

Cosmo: yeah, I've been with my new masters

Cosmo gestured to Kinoko and Izuku. Who were playing around with mushrooms and some weird glowing thingy that Izuku grew

Rocket: master? Your a pet? H-how? Why? Why would you subject yourself to this?

Cosmo: I get what your saying, but they have been nothing but kind to me, they treat me as a family-

Rocket: yeah, and look where that got us... freak animals that don't belong...

Rocket turned around and sat on an empty seat, clearly not wanting to talk anymore

Aizawa got majority of their conversation and hummed to himself

Aizawa: problem creatures... hey, we're almost there

As he said that, the students looked out to see a massive building and looked in awe

Once the bus stopped and opened its doors, the students piled out and looked on even more in amazement

Aizawa: so kids, welcome to the USJ. Here you will be expected to train in rescue training. With help from Thirteen

Thirteen: hello students, welcome

Uraraka gushed at the pro hero as she was a big fan

They entered the USJ and right at the bottom... was an empty field with different areas, with dummies at the bottom to be placed in certain areas

Thirteen: you students will be going into separate areas to save these civilians from different weathers

Kirishima: is thre fake villains as well?

Thirteen: technically as simple card outs but- wait... those aren't... Aizawa

Aizawa: on it, students get out, those are real villains

Izuku: I am Groot?

Kinoko: y-yeah, we should go- oof

Kinoko went to run but ran into a person of smoke

Kinoko: h-hi shroom...

Kurogiri: hello, and goodbye

Kurogiri said as he opened up Portals to separate the students

Izuku clung his arm to Kinoko and to ground away from the portal as Cosmo tried her best to not fall through

Rocket clamped himself onto the portal guy as he saw the opening

Kurogiri: what the- what's on my back? A raccoon?

Rocket: IM NOT A RACCOON!!!!

Rocket screamed as he tassered the nomu with a support item he made

Shigiraki: KUROGIRI! Damnit, Nomu, get them!

A hulking beast called Nomu attacked the raccoon punching it and sending it flying into the wall

Rocket: well... played...

Rocket said before passing out

Cosmo: Rocket! Why you-

The nomu punched Cosmo away

Izulu watched as the nomu punched Cosmo. It readied its fist to punch her again but something snapped inside Izuku

Izuku rushed in and grabbed the nomu's arm as he fought to keep it away from Cosmo

Izuku: I... am... GROOT!

Izuku shouted as he extended his wood over the nomu's arm to force himself on top of the nomu essentially, to try and break it's arms to not attack anyone else

But as soon as the arms broke, they quickly regenerated

Shigiraki: foolish you are, nomu can regenerate

Izuku heard that, but knew there had to be a way to beat it...

Then he remembered something...

The slime incident...

Izuku started to force his wood inside the nomu from the mouth, stretching him out from the inside

The nomu was visibly expanding in size like a water balloon

Shigiraki: wha-whqt are you doing? You- you cheater!

A second later... and the nomu popped with only Izuku's head remaining

Izuku: I *pant* am *pant* Groot *pant*

Shigiraki: and I am pissed

Shigiraki said as he reached for Izuku's head but nothing happened

Shigiraki: right, forgot about you Eraserhead... fffffine, let's head back Kurogiri... retreat...

Kurogiri nodded and ported out of there having woken up after the tazer wore off

Kinoko: I-Izuku! Cosmo!

Kinoko shouted as she ran to Izuku's side and then went to Cosmo to check on them