Forming a party with one's mother in an online game seems not only unlikely but also uncomfortable to most teenage gamers. Unfortunately, Masato Oosuki finds himself in that exact scenario. After completing a seemingly meaningless survey, he is thrown into the world of a fantasy MMORPG—and his mother Mamako actually tagged along with him! On top of all of that, Mamako turns out to be an overpowered swordswoman, possessing the power of two-hit multi-target attacks! After minor tension between the two, they search for party members, meeting the merchant Porta and the sage Wise, starting their journey to clear the game. [Written by MAL Rewrite]

Haruka Nanase has a love for water and a passion for swimming. In elementary school, he competed in and won a relay race with his three friends Rin Matsuoka, Nagisa Hazuki, and Makoto Tachibana. After claiming victory at the tournament, the four friends went their separate ways. Years later, they reunite as high school students; however, Rin couldn't care less about returning to the way things used to be. Not only does he attend a different school, but the sole thing important to him is proving that he is a better swimmer than Haruka. After the bitter reunion, Haruka, Nagisa, and Makoto decide to form the Iwatobi High School Swim Club, but they will need a fourth member if they hope to take part in the upcoming tournament. Enter Rei Ryuugazaki, a former member of the track team whom Nagisa recruits. As the time to compete draws near, the four develop a close bond while training intensely to come out on top and settle things between Haruka and Rin once and for all. [Written by MAL Rewrite]

Five years ago, Musashi made a promise with his friend Kojirou Kanemaki that once they grew up, they would become samurai, form a league, and go on demon-slaying quests. But since then, things have changed. With demons now being praised and worshipped by society, the samurai are shunned and disgraced. Afraid of revealing his dream of becoming a samurai, Musashi blends into the town's dogma by becoming a miner while secretly polishing his swordsmanship. Meanwhile, despite being a direct descendant of a samurai, Kojirou gives up on his promise to his old friend. However, after saving Musashi from a near-death experience, his perspective shifts. Although still conflicted, Kojirou embarks on a journey with Musashi in the hopes of figuring out his true feelings. Fighting against all odds, the duo dives headfirst into the unknown world of beast-slaying, not knowing what life has in store for them. Now astride iron horses, the fifteen-year-old heroes plan to restore the tarnished reputation of the samurai and purge the world of demons.

The continent of Atlatan once again finds itself devoured by the flames of war after a horrific event known as the Great Hall Tragedy. What was supposed to be a joyful occasion that would establish peace between the Fantasia Union and the Factory Alliance, the marriage of Sir Alexis Douse and Lady Marrine Kreische, was instead a tragedy. As the bride and groom walked down the aisle, the ceremony was suddenly interrupted by a powerful convergence of "Chaos," a dark energy from another dimension that corrupts the land and brings forth monsters and demons into the world. From within that energy appeared the Demon Lord of Diabolos, an evil being who instantly murdered the archdukes of both factions, shattering any hope for peace between them. Having failed to prevent this disaster, Siluca Meletes, an Alliance mage, is traveling through the Chaos-infested countryside to study under a master magician. When she is intercepted by a group of soldiers working with the Federation, Siluca is rescued by Theo Cornaro, a young warrior carrying a mysterious "Crest," a magical symbol that gives its wielder the ability to banish Chaos. Bearing no allegiance to a specific domain, Theo hopes to attain the rank of Lord so that he can liberate his home town of Sistina from its tyrannical ruler and the Chaos spreading within it. Impressed by his noble goal, Siluca enters into a magical contract with Theo, and the two embark on a journey to restore balance to their war-torn land. [Written by MAL Rewrite]