While on the road to their field trip, Class 2-C's bus is enveloped in light, and the Goddess, Vicius, summons the students and their teacher to another world. The Goddess hopes to raise them as Heroes to defeat the Great Demon Empire, and she welcomes the students after appraising their abilities with her crystal. However, Mimori Touka is appraised as an E-Class, the lowest rank... and he's branded a trash hero.
Roughly 200 years ago, the efforts of 
the heroes saw this grand evil defeated,
‫قبل 200 سنة، هُزم هذا الشر بفضل مجهودات الأبطال،
Vor 200 Jahren wurde durch die Bemühungen
der Helden das Große Übel bezwungen,
Hace 200 años,
los héroes acabaron con el mal,
Hace 200 años,
los héroes acabaron con el mal,
Il y a deux cents ans, le mal fut défait
grâce aux prouesses des héros précédents,
Duecento anni fa, grazie all'impegno degli eroi,
il Grande Male venne sconfitto,
Há 200 anos, os esforços dos heróis fizeram
com que esse grande mal fosse derrotado,
Два столетия назад
благодаря подвигам героев