With his mother taken away from him and having lost everything, Lag Seeing is now a letter whose delivery has been assigned to Gauche Suede, a Letter Bee. Despite their troubling start, the two of them become friends, leading Lag to realize what his aim in life is: to deliver people's most important feelings in the form of letters, just as Gauche has done.

A long time ago, the ancient saviors of humanity founded a village as their haven, with their descendants said to assist humanity in times of extreme chaos. This village, Kunlun, is located just beside the infamous Last Dungeon—a place where monsters of unimaginable strength reside and which serves as the hunting grounds for Kunlun residents. Despite being accustomed to defeating powerful enemies since childhood, Lloyd Belladonna regards himself as the weakest in his village in terms of magic, strength, and intelligence. Even so, to fulfill his desire of becoming a soldier, he goes to the Kingdom of Azami to enroll in its military academy. However, as someone whose upbringing defies common sense, Lloyd's innate power might just prove to be the key to end the crises enveloping the kingdom!

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.

When Hibio's adventurer mother sets off to research a mysterious tribe, she hits a wall. Fortunately for her, the beautiful young Nima sees a family portrait and decides that she wants her son for her husband and she gets a chance to further her research. She agrees to the arrangement. Of course, she doesn't consult him about his future bride. When Nima shows up in Tokyo to be with her new husband, hilarity and chaos ensues as Hibio and his modern Tokyo background meets Nima's magical heritage. (Source: ANN)