Watch Sword Art Online: Alicization Online

Extra episode of Sword Art Offline included in the Sword Art Online: Extra Edition Blu-ray and DVD.

After vanquishing another boss and stepping through the gates of the fifth floor, the misfit duo Kazuto "Kirito" Kirigaya and Asuna Yuuki are greeted with a beautiful landscape of crumbling ruins and catacombs steeped in mystery. This idyllic adventure is short-lived, however. Tensions between the Dragon’s Knights Brigade and the Aincrad Liberation Squad—the two leading guilds focused on clearing Sword Art Online—continue to rise and threaten the fragile stability of the frontline raiding group. Kirito and Asuna are forced to act quickly, making a desperate gamble and gathering a small number of allies for a dangerous mission. As a result, Asuna and Misumi "Mito" Tozawa must come to terms with their relationship after the near-tragedy that forced them apart on the first floor.

Excelling socially and academically, Asuna Yuuki is on track to ace her high school entrance exams. Her friend and classmate, Misumi "Mito" Tozawa, advises her to take a short break from studying and join her on the launch day of Sword Art Online (SAO)—the highly anticipated online virtual reality multiplayer game. Asuna accepts her offer and soon meets her in the game. In a cruel twist of fate, Asuna, Mito, and every other player logged into SAO find themselves trapped in the game permanently. The only way out is to clear all one hundred floors of the game, and to make matters worse, dying inside the game will kill the player in real life. With SAO now turned into a nightmare death trap, Asuna and other gamers—such as the lone swordsman Kazuto "Kirito" Kirigaya—must adapt and survive, all whilst attempting to beat the unforgiving competition to the top.

Yui wants to see a whale with Kirito during an underwater quest in Alfeim Online. During the quest however, it is revealed Leafa cannot swim. Asuna and the other female characters decide to train Suguha in a real-world pool to help her in ALO. Meanwhile, Kirito meets a certain someone.

Second part of Sword Art Online: Alicization - War of Underworld.