The Generic Isekai Story

A random third year highschool student is summoned to another world. A generic Isekai plot, right?

Hm, what if we change stuff a bit..... He will still be summoned inside a castle, though.

The make his adventure generic and average, but what's this?

"I wanna go home....."

"Haaa.... You can go home after your quest is finished."

"But what if I cannot go home?"

"Just go and find it out yousel- oops."