Ever since the release of the innovative NerveGear, gamers from all around the globe have been given the opportunity to experience a completely immersive virtual reality. Sword Art Online (SAO), one of the most recent games on the console, offers a gateway into the wondrous world of Aincrad, a vivid, medieval landscape where users can do anything within the limits of imagination. With the release of this worldwide sensation, gaming has never felt more lifelike. However, the idyllic fantasy rapidly becomes a brutal nightmare when SAO's creator traps thousands of players inside the game. The log-out function has been removed, with the only method of escape involving beating all of Aincrad's one hundred increasingly difficult levels. Adding to the struggle, any in-game death becomes permanent, ending the player's life in the real world. While Kazuto Kirito Kirigaya was fortunate enough to be a beta-tester for the game, he quickly finds that despite his advantages, he cannot overcome SAO's challenges alone. Teaming up with Asuna Yuuki and other talented players, Kirito makes an effort to face the seemingly insurmountable trials head-on. But with difficult bosses and threatening dark cults impeding his progress, Kirito finds that such tasks are much easier said than done.

Hunters devote themselves to accomplishing hazardous tasks, all from traversing the world's uncharted territories to locating rare items and monsters. Before becoming a Hunter, one must pass the Hunter Examination—a high-risk selection process in which most applicants end up handicapped or worse, deceased. Ambitious participants who challenge the notorious exam carry their own reason. What drives 12-year-old Gon Freecss is finding Ging, his father and a Hunter himself. Believing that he will meet his father by becoming a Hunter, Gon takes the first step to walk the same path. During the Hunter Examination, Gon befriends the medical student Leorio Paladiknight, the vindictive Kurapika, and ex-assassin Killua Zoldyck. While their motives vastly differ from each other, they band together for a common goal and begin to venture into a perilous world.

Sixteen sentient races inhabit Disboard, a world overseen by Tet, the One True God. The lowest of the sixteen—Imanity—consists of humans, a race with no affinity for magic. In a place where everything is decided through simple games, humankind seems to have no way out of their predicament—but the arrival of two outsiders poses a change. On Earth, stepsiblings Sora and Shiro are two inseparable shut-ins who dominate various online games under the username Blank. While notorious on the internet, the pair believe that life is merely another dull game. However, after responding to a message from an unknown user, they are suddenly transported to Disboard. The mysterious sender turns out to be Tet, who informs them about the world's absolute rules. After Tet leaves, Sora and Shiro begin their search for more information and a place to stay, taking them to Elkia—Imanity's only remaining kingdom. There, the duo encounters Stephanie Dola, an emotional girl vying for the kingdom's sovereignty. In desperation, she attempts to regain her father's throne, but her foolhardiness makes her goal unachievable. Inspired by the girl's motivation and passion, Sora and Shiro decide to aid Stephanie in getting Elkia back on its feet, ultimately aiming to become the new rulers of the enigmatic realm.

A year after escaping Sword Art Online, Kazuto Kirigaya has been settling back into the real world. However, his peace is short-lived as a new incident occurs in a game called Gun Gale Online, where a player by the name of Death Gun appears to be killing people in the real world by shooting them in-game. Approached by officials to assist in investigating the murders, Kazuto assumes his persona of Kirito once again and logs into Gun Gale Online, intent on stopping the killer. Once inside, Kirito meets Sinon, a highly skilled sniper afflicted by a traumatic past. She is soon dragged in his chase after Death Gun, and together they enter the Bullet of Bullets, a tournament where their target is sure to appear. Uncertain of Death Gun's real powers, Kirito and Sinon race to stop him before he has the chance to claim another life. Not everything goes smoothly, however, as scars from the past impede their progress. In a high-stakes game where the next victim could easily be one of them, Kirito puts his life on the line in the virtual world once more.