College student Iwatani Naofumi is reading a book titled "The Records of the Four Cardinal Weapons" in the library when he is suddenly summoned to another world and told he has to save the world as the Shield Hero, one of the Four Cardinal Heroes. And one morning, he finds all his money and equipment gone.
and reportedly appear in, 
well, several waves.
ويُذكَر أنّها تظهر على شكل موجات عديدة
die dem Namen entsprechend
in Wellen auftreten.
sur le monde
pour apporter l’apocalypse.
e che, a quanto pare, 
si verificano a intervalli di tempo.
e supostamente são várias ondas.
оставив после себя одни разрушения.