one crazy crossover (Isekai Quartet x Male readers)

Familiar faces

So right now, everyone is in Class 2, as Roswaal announced everyone in front of him.

Roswaal: Fieeeld day is cooooming!

Subaru raises his hand and spoke up.

Subaru: Mr. Roswaal, we just had a field trip, and now it's time for a field day? This schedule is weird.

Emiya: Yeah, isn't it too early for this event, sir?

Kazuma: Yeah, and we barely know what's in this world.

Roswaal: Now, now, work together and win!

Subaru: Do we get something if we win?

Roswaal: Maybe you'll get to go home... Maaaaybe!

Everyone gasped about hearing this and it will be the only chance for them to get home.

Subaru: How are we supposed to win? We're the only ones here.

Roswaal: There is another class next door.

After hearing this, Subaru gets out of the class and goes next door and looks through the window to see a lot of other students.

Subaru: Ehhh?!

Zero: You know i could just get out of this place with a portal and go back to my world since i can do it.

Everyone: EHHH?!?!

Kazuma: When!?

Zero points at Adrian and he was sweating bullets.

Zero: I work part time for him.

Adrian: At least i pay you!

Zero: You havent paid me yet.

Subaru looks through the window to see a lot of new people including the ones from his own world. The red haired man sees Subaru out the window and smirks.

Subaru: Reinhard?

That's when Subaru hears a Man laughter, as he turns to see a Man with blue and white mask.

Vanir: You there, the boy with the nasty loking glare! While you certainly enjoy watching astonishment, I'd appreciate it if you didn't interrupt my class.

Subaru: Who the hell is that?

Roswaal: Okay, back to class everybooody!

Roswaal walks back to class, as Subaru spoke up.

Subaru: They didn't use this to be a classroom here, right?

Ainz: Did you ever seen it?

Tanya: No, it didn't even existed until today...

Zero: I did.

Tanya: When did it happen?

Zero: after the field trip where i wasnt there i felt a lot of people in the other rooms so it must have happened in our field trip.

Class 2

Subaru: The class next door, class 1 seemed to have a few students I recognized.

Gilgamesh: Me and Ainz's combat maids, the Pleiades were there too.

Tanya: So class 1 contains additional residents from our worlds. Then, we should assume that the situation here in this world is in a state of flux. And winning the upcoming field day has become an absolute necessity for us. Well, almost all of us.

Ainz: Correct, Mr. Roswaal says that if we win, we can go back to our old worlds, and then there's Zero who can summon a portal of his and can go home anytime, including his friends.