Mumei is confined in a classroom full of traps. 
Trying to escape along with his comrades, they set off the traps and are sent to another world.
A strange old man was waiting there. 
Mumei's classmates exhaust themselves without skills going up against an enemy that gets stronger the more he drinks.
A sense of foreboding reaches the bewildered Mumei.
I thought you were just 
some dejected old man,
ظننتُك مجرّد عجوزٍ تعيس
Da hatte ich dich nur für ’nen
deprimierten, alten Knacker gehalten,
Pensé que eras un viejo cualquiera,
Pensé que eras un viejo cualquiera,
Je pensais que tu n’étais
qu’un misérable vieillard,
Pensei que você era apenas
 um velhote cansado,