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.

In class 3-3 of Yomiyama North Junior High, transfer student Kouichi Sakakibara makes his return after taking a sick leave for the first month of school. Among his new classmates, he is inexplicably drawn toward Mei Misaki—a reserved girl with an eyepatch whom he met in the hospital during his absence. But none of his classmates acknowledge her existence; they warn him not to acquaint himself with things that do not exist. Against their words of caution, Kouichi befriends Mei—soon learning of the sinister truth behind his friends' apprehension. The ominous rumors revolve around a former student of the class 3-3. However, no one will share the full details of the grim event with Kouichi. Engrossed in the curse that plagues his class, Kouichi sets out to discover its connection to his new friend. As a series of tragedies arise around them, it is now up to Kouichi, Mei, and their classmates to unravel the eerie mystery—but doing so will come at a hefty price.

If not for his ability to take over people's mind and body, Yuu Otosaka would be an ordinary high school student. Though it only lasts for five seconds at a time, Yuu's mysterious power allowed him to cheat his way to the top of his class and enter a prestigious high school, where he continues his dishonest acts. His shenanigans are eventually stopped by Nao Tomori—the headstrong student council president from Hoshinoumi Academy—who sees through his deceit. Through coercion, Nao convinces Yuu to transfer to Hoshinoumi and join the student council. Hoshinoumi Academy is secretly an institution created for adolescents who possess supernatural abilities—with the student council serving as a means of locating those who abuse their powers. With Yuu begrudgingly assisting in council affairs, the group sets out to find and protect new ability users from harm. However, as they further investigate the abilities, their findings entangle them in far more complicated matters than they could ever imagine.

The Great War finally came to an end after four long years of conflict; fractured in two, the continent of Telesis slowly began to flourish once again. Caught up in the bloodshed was Violet Evergarden, a young girl raised for the sole purpose of decimating enemy lines. Hospitalized and maimed in a bloody skirmish during the War's final leg, she was left with only words from the person she held dearest, but with no understanding of their meaning. Recovering from her wounds, Violet starts a new life working at CH Postal Services after a falling out with her new intended guardian family. There, she witnesses by pure chance the work of an Auto Memory Doll, amanuenses that transcribe people's thoughts and feelings into words on paper. Moved by the notion, Violet begins work as an Auto Memory Doll, a trade that will take her on an adventure, one that will reshape the lives of her clients and hopefully lead to self-discovery.