Based on the light novel: the story is about a whole class of students transported to another world, but the protagonist wasn't particularly blessed with skills from the beginning. He gets really strong, overpowered even, through unorthodox ways and ends up having to fight against monsters, battle after battle more difficult than the last. Heroes from another world fighting for humanity against monsters is the gist of the story. Although the protagonist may appear dense, he isn't actually dense in regards to the affections of the heroines around him. Romantic development will happen, slowly and steadily. Regarding the manga, the art kinda moe-tified thecharacters a bit too much compared to the light novel illustrations, making the story feel less serious, but it is still a good manga adaption.