Sword Art Online is an Isekai anime that depicts the life of Kirito Kazuto, after he and all the players of the Virtual MMORPG Sword Art Online are trapped inside the game by its crazy creator, Akihiko Kayaba. Kirito starts the game with much excitement and becomes friends with Klein but, after the devastating twist in which the game had become real, they split up.
Kirito suffers early on in his journey losing many friends and allies but, eventually, he meets Asuna and the two are able to beat the sick game once and for all. This sees the Aincrad Arc, one of the best arcs in the series, come to an end.
10 BEATER 7.7
A month has passed and, after a massive amount of death, the people of Aincrad decide to meet up to discuss how they should move forward. A large number of people gather inside a colosseum and they try to develop a strategy for defeating the boss of the first floor. It is in this episode that the audience learns of the resentment some players have with those who beta tested the game. When the large group finally confronts the floor boss, they are met with a very difficult battle in which most of the group struggles to survive. But, due to the combined effort of Kirito and Asuna, they manage to make it out alive.
9 THE WARMTH OF THE HEART 7.7
After carelessly breaking Lisbeth's sword, Kirito is scolded by Lisbeth. To escape from her complaints, he quickly switches the topic. This leads Kirito informing her that he's come to her in hopes she could build a sword even stronger than his Elucidator. Kirito then joins Lisbeth on a mission to gather materials necessary to build a much stronger sword. While on the mission, they encounter a dangerous dragon who manages to corner them, before forcing them to dive into a cave. The two eventually escape and make it back to Lisbeth's shop where she crafts the weapon.
8 YUI'S HEART 7.7
After returning to the Starting Town in search of Yui's family, Kirito and Asuna learn that she isn't from this town, and with her continued amnesia, they are out of clues. Word of Kirito and Asuna's skills get out and Yulier, a member of the Aincrad Liberation Army, comes searching for help to rescue her boss, Thinker. Thinker was betrayed by a comrade and is now deserted in a dungeon. After some pleas from Yui, Kirito and Asuna decide to help. They manage to rescue Thinker and, during the mission, Yui's past is revealed.
7 THE RED-NOSED REINDEER 7.9
This episode begins with Kirito's group of adventurers holding a party in his thanks, due to him saving their lives on their last mission. They then invite Kirito to join their guild and, much to the audience's surprise, he jumps at the opportunity. After doing a bit of adventuring together, they grow as a unit. but Kirito notices that one of the group's member has been acting a bit weird. After confronting her he realizes that it's due to a great fear of dying while trapped in Aincrad. The team later goes on a mission and only Kirito makes it back alive, this tragedy results in a deep change in the series protagonist.
6 THE BLACK SWORDSMAN 7.9
After leaving her party. Silica is attacked in the forest by a random monster but, fortunately, she is rescued by Kirito. Despite saving her, Kirito couldn't manage to save her familiar, which saddens Silica deeply. To help the girl feel better, Kirito offers his assistance and the two head out on an adventure. This adventure proves fruitful but they encounter danger along the way, this time in the shape of a group of players that go around murdering other players. When his group confronts Silica to kill her, Kirito again rescues her, before defeating the player killers.
5 THE DEPTHS OF HELL 7.9
This episode is evenly split into two parts. The first half of the episode depicts Asuna and Kirito's peaceful family life back at their home. Here, the audience gets to see how Kirito and Asuna engage with citizens and NPC's when away from combat. The second half of the episode focuses on the adventurers' battle against another floor boss, this one even more deadly than the last. The adventures do their best, but many of them get wiped out in the early part of this fight. The combined efforts of Kirito, Asuna and Heathcliff temporarily stop the monster before he begins yet another rampage, driving the adventurers back.
4 THE WORLD OF SWORD 8.2
This is a solid opening episode that introduces the audience to the story and some characters that will be crucial to how the plot develops. Klein manages to befriend Kirito (a beta tester), who gives him instructions on how to use the game's mechanics more effectively. This goes well and Klein is able to kill a couple of monsters. This is then juxtaposed against the awful revelation of the game's true nature. The creator appears in front of the players and explains that they are now stuck inside the World of Sword Art Online, and the only way to escape is to beat the game. Nevertheless, if you die, there's no coming back.
3 SEEING RED 8.3
Heatcliff informs Kirito that if he wishes for Asuna to leave the Knights of the Blood Oath, he must first defeat him in a duel and if he loses, he must then join the Knights. Kirito engages in an exciting duel with Heatcliff before suspiciously losing due to some sort of trick from Heatcliff. After Kirito joins, he's forced to go on a mission. One of his guildmates betrays his guild and attempts to kill Kirito and Godfree. Unfortunately, Godfree dies but Asuna manages to save Kirito. The two then resolve to be by each other's side for the rest of their lives.
2 THE BLUE-EYED DEMON 8.4
This episode opens with Kirito and Asuna on a scouting mission to gather information on the next boss monster. They enter his floor room and briefly get a look at him before running away due to the danger of confronting it without enough numbers. On their way out, they encounter Klein, who falls for Asuna before realizing that she and Kirito are now a thing. The two parties are then interrupted by random adventurers who want information on the boss. Kirito shares this information before warning them not to press on with their inadequate numbers. The commanding officer decides to charge right into the final battle, and his troops are immediately cornered. After a few seconds, they are all low on HP and it falls on Asuna and Kirito to save them.
1 THE END OF THE WORLD 8.8
Kirito has been distrustful of Heatcliff ever since he was defeated in a suspicious manner. After another hard-fought battle against a floor boss, Kirito charges at Heatcliff before thrusting his sword at his neck, but Heatcliff easily blocks it. In doing so, it is revealed that he is no other than Akihiko Kayaba, the game developer and de facto, god of the world. He announces that he was scheduled to be the final level's boss but, now that he has been uncovered, he challenges the players then and there. Kirito manages to defeat him, returning himself and all the trapped players to reality.