The Soul Translator is a interface which interacts with the user's Fluctlight—the technological equivalent of a human soul—and fundamentally differs from the orthodox method of sending signals to the brain. The private institute Rath aims to perfect their creation by enlisting the aid of Kazuto Kirigaya. He works there as a part-time employee to test the system's capabilities in realm generated by the Soul Translator. As per the confidentiality contract, any memories created by the machine in the virtual world are wiped upon returning to the real world. Kazuto can only vaguely recall a single name, Alice, which provokes a sense of unease.

When Kazuto escorts Asuna Yuuki home one evening, they chance upon a familiar foe. Kazuto is mortally wounded in the ensuing fight and loses consciousness. When he comes to, he discovers that he has made a full-dive into the Underworld with seemingly no way to escape. He sets off on a quest, seeking a way back to the physical world once again.

In the year 2022, a massive online role-playing game called Sword Art Online (SAO) is launched. With the aid of "NerveGear" technology, players can control their avatars within the game using nothing but their own thoughts.

Kazuto Kirigaya is among the lucky few who get their hands on the first shipment. He logs in to find himself, with ten-thousand others, in the scenic and elaborate world of Aincrad. However, in a cruel turn of events, the players soon realize they cannot log out; the game's creator has trapped them in his new world until they complete all one hundred levels of the game.

In order to escape Aincrad, Kirito will now have to interact and cooperate with his fellow players. Some are allies, while others are foes. Sword Art Online is not all fun and games: if they die in Aincrad, they die in real life. Kirito must adapt to his new reality, fight for his survival, and hopefully break free from his virtual hell.

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.

A special recap of the first season with an original story in which Kirito and the others decide to go on an underwater mission so that Yui can see a whale, but they face a shocking revelation... Suguha is afraid of water. So Asuna and the other girls decide to teach Suguha how to swim. Meanwhile, Kirito is meeting somebody.

桐人、尤吉欧、爱丽丝。距离两名修剑士和一名整合骑士打败了最高祭司阿多米尼斯多雷特已过去了半年。
结束了战斗，爱丽丝在故乡卢利特村生活。在她的身旁，是失去了挚友，自己也失去了手臂和心的桐人。
献身般支撑着他的爱丽丝，丝毫没有保留像以前一样作为骑士的心。
“告诉我，桐人……我究竟该怎么办？”
然而，通往将Underworld全境引向悲剧的“最终压力测试”的倒计时，却毫不留情地推进着。
仿佛与之相呼应一般，在“黑暗领域”的深处，暗黑神贝库达复活了。他率领暗黑帝国的军队，为了得到“光之巫女”，开始向“人界”进攻。
指挥“人界”军队的贝尔库利等人，决心与“黑暗领域”的军队展开前所未有的大战。
但在他们身旁，并没有发现爱丽丝，以及拯救了“人界”的两位英雄的身影。
《刀剑神域》系列最长、拥有最华丽战斗的“Alicization”篇，其最终章终于揭幕！

以《最终负荷实验》为名，将Underworld全土卷入的《人界》军与暗之军势的战争。
战局逐渐转变为企图夺取《光之巫女》爱丽丝的《黑暗领域》军加百列一派，
与致力于守护Underworld的《人界》军亚丝娜等人之间的战争。
在桐人仍然沉睡于精神世界的深处之时，《暗黑神贝库达》即加百列
从现实世界中让数万美国玩家登录，企图一举歼灭《人界》军。
相对地，亚丝娜等人利用以Underworld创世神冠名的3个超级账号展开对抗。
获得了《创世神史提西亚》超级账号的亚丝娜，
和《人界》军一同与美国玩家展开死战，
而获得了《太阳神索鲁斯》超级账号的诗乃，则追赶着带走了爱丽丝的加百列。
随后，获得了《地神提拉利亚》超级账号的莉法，也抵达了Underworld。
不仅如此。呼应了莉兹贝特充满气势的演说的《ALO》玩家们，
将千锤百炼的角色进行转移，加入《人界》军一方参战！
这场大战不只关系到Underworld的存续。
还是赌上了作为究极AI的自律学习型人工智能，甚至人类未来的战斗。
而大战的终点，如今正握在沉睡中的一名少年——《黑色剑士》的手中。
《Alicization》篇，在此完结！

2021 film directed by Ayako Kōno