The solo player: Kirito, who had the luck-of-the-draw to play the beta version, was imprisoned along with many other players of Sword Art Online (SAO) inside of a game, unable to logout; the only way to live is to win. Death in-game means death in the real world, due to tampering with the Nerve Gear; the console that simulates the in-game character controls by redirecting brain signals. Escaping the death game requires the defeat of the final boss on the top floor, two years later; out of the original 10,000 players at the start, only 6000 remain and 26 floors left to clear.
A huge castle made of stone and steel floating in an endless sky.
That was all this world was.
It took a vagarious group of craftsmen one month to survey the place; the diameter of the base floor was about 10 kilometers — large enough to fit the entirety of Setagaya-ku within. Above, there were 100 floors stacking straight upwards; its sheer size was unbelievable. It was impossible to even guess how much data it consisted of.
Inside, there were a couple of large cities along with countless small scale towns and villages, forests and plains, and even lakes. Only one stairway linked each floor to another, and the stairways existed in dungeons where large numbers of monsters roamed; so discovering and getting through was no easy matter. However, once someone made a breakthrough and arrived at a city of the upper floor, the «Teleport Gates» there and of every cities in the lower floors would be connected making it possible for anyone to move freely through these levels.
With these conditions, the huge castle had been steadily conquered for two years. The current front line is the 74th floor.
The name of the castle was Aincrad, a world of battles with swords that continued floating and had engulfed approximately six thousand people. Otherwise known as…
Kirito, after fighting a Level 82 Lizardman Lord, recollects what happened two years ago.
Klein asks for Kirito’s guidance after he realizes that Kirito was one of the one thousand participants of the «Sword Art Online Closed Beta». After Klein successfully defeats a «Frenzy Boar», he tries to log out because he ordered pizza. Failing to find the logout button, Kirito and Klein discuss the implications of the “unable to logout bug”.
Without warning, they were both teleported to the central plaza of «Starting City». The GM Kayaba Akihiko informs them that the only way to logout is by clearing all one hundred floors of the floating city of «Aincrad», and that death in-game means death in real life.
Kirito, realizing that there will be shortage of monsters near «Starting City», urges Klein to leave the village along with him. Klein asks Kirito whether they can take his friends along. Kirito, unable to bear the heavy burden of Klein and his friends’ lives, wordlessly disagrees. They separate after Klein decides to help his real life friends.
Almost a month into the game, 2000 players have died. The remaining players are divided into four groups. Non-players, army, wasters who later join the army, and guilds. Only a mere fraction are solo players.
Kirito successfully kills a super rare monster Ragout Rabbit and teleports to Algade to sell the «Ragout Meat». He later decided against selling the Meat after talking with the shop owner Agil and meeting Asuna the «Flash»; sub-leader of the guild known as the Knights of the Blood. He agrees with her cooking the ingredient in her house in exchange of giving her half the meat. Asuna order her subordinates that she will be leaving for the day, displeasing her bodyguard: Kuradeel. He directs his anger to Kirito after realising he is a «Beater» (Combination of a «Beta tester» and «Cheater»). Asuna, disgusted with Kuradeel’s actions, orders him to leave. She ends the conflict by leaving with Kirito through the crowd.
Kirito journeys with Asuna to her home in the 61st floor to cook the «Ragout Meat». Upon arriving, Asuna prepares the meal with her maxed out cooking skill. After enjoying the gourmet meal with the taste synthesized by the «Taste Reproduction Engine», Asuna later persuades Kirito into forming a party with her.
An unhappy Kirito was waiting for the late arriving Asuna at their specified meeting place. Asuna, running away from her bodyguard Kuradeel, bumps into him while using a teleportation crystal. Kuradeel, who strongly disagrees of her recent actions try to take her back to their guild headquarters. Kirito intervenes for Asuna’s sake and enters a 1-on-1 duel against Kuradeel. Kirito easily wins the match by breaking Kuradeel’s decorated two-hand sword. Kuradeel, enraged by his defeat, threatens to kill Kirito. Asuna orders Kuradeel to return to «Grandzam» to prevent things from escalating any further. Asuna later apologises to Kirito for the trouble.
Kirito and Asuna were dicussing each other’s taste in clothing until Kirito noticed the movement of numerous flashing green cursors on his virtual scanner. With both of them hiding under Kirito’s coat, they hide themselves behind the trees as they watched the 12 players from the guild The Army march past. Asuna then informs Kirito about the change in behavior of «The Army». Both fear that «The Army» might try the suicidal task of challenging the yet discovered boss of the 74th floor with no intel and with only 12 men. Kirito and Asuna make their way into the Labyrinth Area.
The «Knights of the Blood» was known as the best guild in over a year; the leader of the guild, the «Man of Legend» Heathcliff, and the sub-leader Asuna the «Flash» were both renowned as two of the best warriors in Aincrad. Kirito thought about this as he was teaming up with Asuna against the common skeleton enemy: the «Demonic Servant»; both display their excellent teamwork with a skill known as «switching» against their common foe. As they map the dungeon, they soon come across the eerie looking door of the boss room. After a few minutes of hesitation, they peek inside and look for the dweller of the dark room; there their eyes met with The Gleam Eyes, the boss of the 74th floor.
Asuna and Kirito take a break at the safe zone of the labyrinth; both of them eating Asuna’s handmade sandwiches. Kirito licks her fingers after tasting a flavor that’s something similar to the outside world. Klein enters the labyrinth and sees Kirito and Asuna together. Their conversation is later interrupted by the presence of the «The Army» troops. After claiming Kirito’s mapping data, «The Army» troops march away and into the labyrinth. Kirito and the group decided to follow after them after worrying that «The Army» may challenge the boss by themselves despite their earlier warning.
«The Army» had challenged the boss and was suffering from their mistake; crystal usage was prohibited in the boss room and «The Gleam Eyes» was blocking the exit. Kirito and the others enter to provide support. Backed into a corner, Kirito was forced to used his secret «Unique Skill» Dual Blades. Never has anyone seen Kirito use such a thing like that. Kirito manages to defeat the floor boss, with his HP bar in the red zone.
As his story has not yet ended; the fallen Kirito awoken to find Asuna crying while holding him. The remaining members of «The Army» return to their base to report the incident, and the honour of establishing the link to the next floor was left to Klein and his group. Asuna decided to take a momentary break from «KoB» and plan to stay with Kirito for a little longer.
As the hidden unique skill: «Dual Blades» was now known to the public, and the sudden rise in fame; Kirito went into hiding from the persistent crowd at the second floor of Agil’s shop, waiting for Asuna to return from the «KoB». A new problem arises when Heathcliff; «the Living Legend»; leader of the «KoB» wishes to duel with the now famous Kirito for the sake of Asuna.
Today presents the grand event of the duel of the two «unique skill» wielders: the «Dual Blades» vs. the Holy Sword; Kirito accepted Healthcliff’s challenge, under the conditions that Asuna will be given to him if he wins, and joining the «KoB» if he loses. The match proceeded with each other scything one another’s life-span, with varying chances that the winner can be either one. The match ended with Kirito’s loss, as the man of legend performed an impossible move that momentarily broke the game.
As Kirito was a man of his word, he now joins the «KoB»; already disliking the blinding white uniform that was in contrast to his usual black coat. Much to Asuna’s surprise, Kirito confessed about the tragic end of his first guild: the Black Cats of the Full Moon; still believing that he was the trigger of their demise. Feeling his sorrow, Asuna comforted Kirito during his time of guilt.
On the first day on the job, Kirito had to attend a mandatory training course to present his skills. To Kirito’s dismay, he discovers that he had to work alongside with the least person he wanted to see: Kuradeel.
After Kirito relinquishes all of his crystals following Godfrey’s order, the group adventures to the 55th floor training area. At the time of their break, Kuradeel attempted his assassination after lacing the drinking water with paralysis poison; killing one after another until the paralysed Kirito was left alone with the murderous Kuradeel, who turn to be one of last remaining members of the worst Player Killing guild: Laughing Coffin.
Despite the paralysis, Kirito struggled near to his death against Kuradeel and was rescued by the soaring Asuna, allowing Kirito to finally recover. Demonstrating why she earned the name of the «Flash», she reaps his health near to its end before allowing his surrender. To protect Asuna, Kirito ended Kuradeel’s life by stabbing deep into him with his hand. At the end, Kirito told Asuna that he would offer his life to her, and will stay with her to the very end.
It turns out that Asuna was monitoring the map while waiting at the 55th floor city: Grandzam. Asuna and Kirito reported to Heathcliff about the incident, and temporarily left the guild with his permission. As Kirito did not want to be alone at the moment, he carelessly told Asuna that he want to be with her that night, which led to a comical chain events and draws some attention to an interesting option on their virtual menu screen called «Ethic Code Off». After some time, Kirito finally unveil his feelings to Asuna and made his proposal to her for marriage.
Kirito and Asuna are now in the relationship of marriage in Aincrad, and spending their newly-wed life at a small, round cottage on the 22nd floor. Once again, both announce their love for one another.
10 days have passed; both Kirito and Asuna push aside their fighting skill for the moment, and decided to train their domestic skills; Kirito on fishing, and Asuna on sewing. As luck would have it, Kirito seem to have spent it all in getting Asuna to marry him as no fish would bite. They soon met a fisherman name Nishida, and decided to help him carry out a fishing event on a later day.
It was the day of the fishing event; not only was Nishida, Kirito and Asuna were present but a crowd was waiting attentively for the appearance of the local god. Nishida uses his highly trained fishing skill to get the bite, and then switches for Kirito’s superior strength. What they caught however was an enormous Coelacanth monster which Asuna soon over-kill. The event ended and so was their honeymoon, as they were requested to attend the boss raid by Heathcliff the following day.
Kirito and Asuna returned to the «KoB» headquarters to learn of the demise of a scouting party from Heathcliff; the room of the 75th boss was discovered, however no Intel about the boss was obtain. Upon passing the gate, the boss room will isolate itself and the use of teleportation crystal will be prohibited. Despite the applied grim conditions, Heathcliff still plan to attack the boss with his strongest members and hope for the assistance of Kirito and Asuna.
Klein and Agil were amongst the group of high level players who gathered for the boss raid; including Kirito, Asuna, and Heathcliff. The tension rises as the man of legend lead the group through the gate of the rare «Corridor Crystal», they trespass into to the boss room with 32 players and awaited the gate to close behind. Within the isolated room, the battle commences against the skeletal centipede who can kill a player with one strike; The Skullreaper.
The battle continued for over an hour until the fall of «The Skullreaper»; the deadliest foe so far who easily eliminated 14 players. Everyone grief about whether it was possible to complete this game, as the fatalities and difficulties will certainly rises in the coming battles. Suddenly thanks to Kirito’s intuition, the true identity of the immortal Heathcliff was discovered. Before leaving after immobilising everyone with the authority of the system administrator, Heathcliff decided to challenge Kirito with a one-on-one duel to the death for everyone’s freedom, which Kirito boldly accepted.
The battle rages on with the unyielding actions of Kirito and Heathcliff; both accelerating their skills to an intense manner; and it continues until Kirito commits the mistake of trusting a skill guided by the system. As the match draw near to a close, an impossible event occurs; the last attack that would have ended Kirito’s life was redirected onto the supposed immobilised Asuna who shielded him. The attack depleted the last of her remaining health, and as the one truth imagined in this world, she perished from within Kirito’s arm.
With the loss of Asuna, Kirito lost his state of mind and fought with no longer caring for his life. After Heathcliff pierce Kirito with his blade and ended his life, the dying Kirito perform his last act by using Asuna’s sword to kill Heathcliff from point blank. The battle resulted with the deaths of the two duellists and the friends of Kirito witnessing the destruction of both bodies. The infamous last boss was eliminated and thus the game was cleared.
Kirito finds himself staring at the steel castle in another world alongside Asuna; watching as the game executes the Final Phase; the destruction of Aincrad. They both were soon interrupted by the presence of Kayaba Akihiko; the man who started it all. After explaining his motive for the death game, he left the two lovers: Kirigaya Kazuto and Yuuki Asuna for the departed world.
Kirito was finally freed from the game. After finding himself in the hospital, he left his bed. His body frail and weak, but he will not rest until he have Asuna back in his arms.