Iwatani Naofumi, 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?

The curtain rises on a fantasy adventure about the rise of a man who has lost it all.

[Source: Crunchyroll]

Naofumi Iwatani, an ordinary college student, is summoned to another world as one of the Four Cardinal Heroes—the "Shield Hero". Despite false accusations and a series of misfortune, Naofumi joined forces with his dear companions Raphtalia, Filo and Melty, to protect people from the "Waves" of Catastrophe.

With his achievements and help from Queen Melromarc, Naofumi regains his honor and now owns a territory. He prepares to counter the next Wave.

However, it is said that the "Spirit Tortoise", a monster that will bring forth an unprecedented disaster, has been resurrected in the country of Spirit Tortoise Kingdom, east of Melromarc.

Upon a request from the Queen to subdue the Spirit Tortoise, Naofumi sets off for the Spirit Tortoise Kingdom, along with his new party member, Lecia.

While the allied forces gather, Ost-Horai, concubine to the King of the Spirit Tortoise Kingdom and regent of the country, appears before Naofumi.

She informs Naofumi of a person who forcefully resurrected the Spirit Tortoise.
Will Naofumi subdue the Spirit Tortoise and reach the mastermind?

The Shield Hero stands up once again to protect the things dear to him.

[Source: ANIPLUS Asia]