The Four Cardinal Heroes are a group of ordinary men from modern-day Japan summoned to the kingdom of Melromarc to become its saviors. Melromarc is a country plagued by the Waves of Catastrophe that have repeatedly ravaged the land and brought disaster to its citizens for centuries. The four heroes are respectively bestowed a sword, spear, bow, and shield to vanquish these Waves. Naofumi Iwatani, an otaku, becomes cursed with the fate of being the "Shield Hero." Armed with only a measly shield, Naofumi is belittled and ridiculed by his fellow heroes and the kingdom's people due to his weak offensive capabilities and lackluster personality. When the heroes are provided with resources and comrades to train with, Naofumi sets out with the only person willing to train alongside him, Malty Melromarc. He is soon betrayed by her, however, and becomes falsely accused of taking advantage of her. Naofumi then becomes heavily discriminated against and hated by the people of Melromarc for something he didn't do. With a raging storm of hurt and mistrust in his heart, Naofumi begins his journey of strengthening himself and his reputation. Further along however, the difficulty of being on his own sets in, so Naofumi buys a demi-human slave on the verge of death named Raphtalia to accompany him on his travels. As the Waves approach the kingdom, Naofumi and Raphtalia must fight for the survival of the kingdom and protect the people of Melromarc from their ill-fated future. [Written by MAL Rewrite]

The Abyss—a gaping chasm stretching down into the depths of the earth, filled with mysterious creatures and relics from a time long past. How did it come to be? What lies at the bottom? Countless brave individuals, known as Divers, have sought to solve these mysteries of the Abyss, fearlessly descending into its darkest realms. The best and bravest of the Divers, the White Whistles, are hailed as legends by those who remain on the surface. Riko, daughter of the missing White Whistle Lyza the Annihilator, aspires to become like her mother and explore the furthest reaches of the Abyss. However, just a novice Red Whistle herself, she is only permitted to roam its most upper layer. Even so, Riko has a chance encounter with a mysterious robot with the appearance of an ordinary young boy. She comes to name him Reg, and he has no recollection of the events preceding his discovery. Certain that the technology to create Reg must come from deep within the Abyss, the two decide to venture forth into the chasm to recover his memories and see the bottom of the great pit with their own eyes. However, they know not of the harsh reality that is the true existence of the Abyss. [Written by MAL Rewrite]

After dying a laughable and pathetic death on his way back from buying a game, high school student and recluse Kazuma Satou finds himself sitting before a beautiful but obnoxious goddess named Aqua. She provides the NEET with two options: continue on to heaven or reincarnate in every gamer's dream—a real fantasy world! Choosing to start a new life, Kazuma is quickly tasked with defeating a Demon King who is terrorizing villages. But before he goes, he can choose one item of any kind to aid him in his quest, and the future hero selects Aqua. But Kazuma has made a grave mistake—Aqua is completely useless! Unfortunately, their troubles don't end here; it turns out that living in such a world is far different from how it plays out in a game. Instead of going on a thrilling adventure, the duo must first work to pay for their living expenses. Indeed, their misfortunes have only just begun! [Written by MAL Rewrite]