The series is set in a world with an alternate history, where magic exists and has been polished through modern technology. However, the ability to use magic is determined by genetics, limiting the number of magicians in existence. Following the Third World War, the world’s superpowers shifted to these four nations: The United States of North America (USNA), New Soviet Union, the Great Asian Alliance, and Japan. In Japan, the magic community is informally governed by the ten master clans in lieu of the government. Due to the limited number of magicians, they are treated as a commodity and are forced to enter magic related schools and professions. Nine magic high schools exist in Japan; they each specialize in different aspects of magic and are simply referred to by their numbers.

The story follows Tatsuya Shiba, a bodyguard to his sister Miyuki Shiba who is also a candidate to succeed in the leadership of the Yotsuba clan, one of the Ten Master Clans that govern Japan’s magicians. They enroll at First High School which segregates its students based on their magical abilities. Miyuki is enrolled as a first-course student and is viewed as one of the best students, while Tatsuya is in the second course and considered to be magically inept. However, Tatsuya’s technical knowledge, combat abilities, and unique magic techniques cause people to view him as irregular to the school’s standardized rankings.

A year has passed since Sword Art Online (SAO) was cleared. Kirito is asked by Kikuoka to investigate Gun Gale Online, specifically Death Gun, a weapon which seemed to link deaths in the virtual reality world to those in the real world.

Upon entering the game, Kirito meets Sinon who teaches him the ropes of the game. They both enter the Gun Gale Online tournament, Bullet of Bullets. Kirito displays his amazing skills although he is only a newcomer to the game. Later, Kirito finds out that the mysterious deaths are linked to a red guild named Laughing Coffin in SAO.

In 2026, two years since the SAO incident, a new game called “Ordinal Scale,” an Augmented-Reality MMO, is becoming popular among the players. But strange things are happening in the game and Kirito and the gang are facing a new danger.