Manga Volume 1

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction. As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world! Amazon

Summary
Iwatani Naofumi has just been summoned to Melromarc along with three others, Kitamura Motoyasu, Amaki Ren, and Kawasumi Itsuki, for the purpose of being the new heroes. He is gifted with the Legendary Shield which validates him as the Shield Hero. Although he is reluctant to help and does not see how a shield can be considered a weapon he realizes that in order to return to his old world he would have to survive long enough in this one to either find a way to return or resolve the crisis present in this new world. He resolves himself to assist in any way he can and despite some minor inconsistencies in the general treatment he receives, everything seems to be working out well for him. He receives money from the king to begin his journey and even manages to secure a companion, Malty. Even though the other three Heroes have more he's still grateful and looks towards the future with optimism.