"Everyone looks pretty grown-up after summer break"
Shinpachi finds himself in stuck in a completely different world.  That is when the Shinsengumi sends a berserk Yamazaki to pick up the bewildered Shinpachi.
We're the only ones stuck in a completely different world.
Somos los únicos atrapados en un mundo completamente diferente.
Somos os únicos nesse mundo 
completamente diferente.