The Shield Hero is the first episode of The Rising of the Shield Hero anime.
Naofumi Iwatani, a run-of-the-mill otaku, finds a book in the library that summons him to another world. He is tasked with joining the sword, spear, and bow as one of the Four Cardinal Heroes and fighting the Waves of Catastrophe as the Shield Hero. Excited by the prospect of a grand adventure, Naofumi sets off with his party. However, merely a few days later, he is betrayed and loses all his money, dignity, and respect. Unable to trust anyone anymore, he employs a slave named Raphtalia and takes on the Waves and the world. But will he really find a way to overturn this desperate situation?
Finding a library fantasy book about "Four Heroes", otaku college student Naofumi Iwatani is summoned to another universe along three other boys to save mankind from a prophesied evil, a series of Waves that unleash monsters when they open, in the roles of the Four Heroes from the book. Each equipped with Legendary Weapons- Sword, Bow, Spear, and Shield -, with interface functions similar to an MMORPG, they must go on separate quests as neither can upgrade due to the weapons preventing XP gain in proximity to each other. When partners are assigned, nobody wishes to join Naofumi, as he is seen as the weakest. But Myne, a member of the Spear Hero's party, offers to join Naofumi to help him train, shop and equip. On the third day of his journey, Myne robs him blind, frames him for rape, and forces Naofumi to live as an outcast. As nobody would hear his defense, Naofumi becomes angry and bitter at the world; he scrounges for materials, and learns how to upgrade his shield with resources he finds in this world. The only person who shows him any courtesy is the weapon-smith he met the day before, who could tell Naofumi wasn't as he was accused of. After fighting away some thugs who wanted to rob him, he realizes that he's in a feedback loop: he can't upgrade without experience, no experience without strength, and no strength without upgrading. From the shadows, a slave trader greets him, and invites him to a slave market to offer a slave to serve him so he may gain XP and fight. In the corner of the room, Naofumi locates a little slave girl.