On June 28, 2026, having encountered Kanamoto Atsushi, the last remaining member of Death Gun, equipped with a syringe of succinylcholine that he planned to use against them, while escorting Yuuki Asuna home, Kirigaya Kazuto pushed his girlfriend away to safety as he intercepted the man's attack with his umbrella. However, the boy was injected with the drug during the brawl, causing him to collapse due to cardiac arrest. Witnessing this event, Asuna momentarily recalled a similar scene during her time Sword Art Online two years prior, during which she had been protected by Kirito from a Laughing Coffin member's attack.
Having accompanied her injured boyfriend to the Setagaya General Hospital for treatment following the attack, Asuna waited in front of the operating room for Kazuto's surgery to be complete, being joined by Kirigaya Midori and Kirigaya Suguha just as she sat down. When the procedure was completed the next morning, the doctor informed them that although the operation saved Kazuto's life, the boy might have sustained permanent brain damage due to the long period of cardiac arrest. As Midori was signing the paperwork to transfer Kazuto to a better facility for magnetic resonance imaging, Asuna and Suguha were approached by Kikuoka Seijirou, who wished to speak with Kazuto's parents.
That evening, Asuna and Suguha arrived at the National Defense Medical College Hospital, the institution where Kazuto was supposed to be currently hospitalised under Seijirou's advice; however, they were not allowed to see the boy. The following day, Asuna and Leafa met Lisbeth, Silica, Sinon in ALfheim Online (ALO), where the two informed the girls that the hospital refused to allow their visit due to Kazuto being treated with specialized equipment at the time. However, feeling suspicious about the claim, the two investigated the matter further and thus discovered that Kazuto's ambulance had never arrived at its destination, despite the boy being admitted to the hospital according to the records.
As Seijirou had disappeared that same day and had access to a device that could connect to the user's soul itself, the girls speculated that Kazuto could have been transported to one of Rath's facilities with a Soul Translator. At that moment, Asuna informed the other girls that she had requested Yui to analyse the data of an application connected to sensors implanted in Kazuto's chest as part of his job, in hopes of finding something that could lead them to his current location. Prompted by Asuna, the Navigation Pixie reported that Kazuto's last known position was in Minato Ward, at around 21:20 the day before.
Later that same day, Asuna and Suguha requested Tsuboi Ryoutarou (Klein) to drive them to Kazuto's last known position at the Shinagawa Wharf in Minato Ward, hoping to find more clues as to Kazuto's whereabouts. Following Rika's (Lisbeth's) report from Roppongi that the cameras around Rath's office there had not seen Kazuto, Yui reported that a helicopter had departed from Shinagawa Wharf the moment when Kazuto's signal was lost, much to Asuna's sorrow.
Encouraged not to lose hope by Yui, Asuna continued to search for other hints to Kazuto's whereabouts by asking Suguha if she recalled hearing anything about Rath from her cousin. This led to Asuna learning that the Soul Translator was based on the Medicuboid, a FullDive device for medical purposes created by Kayaba Akihiko and his acquaintance, Koujiro Rinko. The latter, according to Yui's investigation, was a researcher at a university in California, as well as a member of the laboratory that Kayaba Akihiko had worked at, prompting Asuna to speculate that she might have knowledge about the Soul Translator and Rath.
The following evening in California, while checking her mailbox, filled with invitations from Kikuoka Seijirou to participate in his project, Rinko reminisced about her days with her lover, Kayaba Akihiko. The man had once shared his lifelong dream: a large castle, consisting of multiple floors with a palace at the very top. Moments after finishing her reminiscence, Rinko was alerted to a new e-mail having arrived to her mailbox. To her surprise, however, e-mail was sent by a person named Yuuki Asuna, rather than being another message from Kikuoka Seijirou.
Several days later, Koujiro Rinko and her assistant Megumi Reynolds were flown to the Ocean Turtle, Rath's secret base in the ocean. Upon landing, the two were greeted by Lieutenant Nakanishi, who escorted them to a control room-like area after numerous security procedures. There, the women met Kikuoka Seijirou and Higa Takeru, Rinko's former colleague from the Shigemura Lab. Stating that the project now had all three individuals he believed to be indispensable for it, two of whom were Rinko and Takeru, Seijirou shared his hope to be able to introduce them to the third person in a few days, as he was currently unavailable.
At that very moment, Megumi Reynolds discarded her disguise, revealing her true identity as Yuuki Asuna. Due to Seijirou's astonishment, Rinko explained that the young girl had informed her about the Soul Translator and Kazuto's disappearance in order to request her help in reuniting with the boy. Once the two women explained how they had bypassed Rath's security to allow Asuna to infiltrate the base, the girl demanded the whereabouts of her beloved with a serious expression.
Laughing Coffin raid flashbacks were anime original scenes.
The entire scene of Kazuto being loaded in an ambulance and his heart stopping was omitted.
In the light novel, Asuna did not notify Suguha and Midori until after Kazuto's operation was over.
Therefore, the scene of Asuna, Suguha and Midori at the hospital was anime original content.
The scene of Seijirou convincing Midori to place Kazuto under his jurisdiction and supposedly transfer him to a military hospital was anime original content.
In the light novel, Lisbeth and Silica were not present at Asuna's, Leafa's and Sinon's meeting in ALfheim Online.
In the light novel, Asuna, Leafa and Sinon quickly deduced Kirito was at the Ocean Turtle from information previously given to them by him at the Dicey Cafe and news reports on the facility.
Therefore, the scenes where Asuna, Suguha and Ryoutarou search the harbor while Shino, Rika and Keiko check Rath's facility in Tokyo was anime original content.
In the Light Novel, Yui also explained the concept of «Top-Down AI» and «Bottom-Up AI» at Asuna, Leafa and Sinon's meeting, using herself as an example of «Top-Down AI».
The scene of Rinko's and Akihiko's past relationship was anime original content.
The scene of Rinko receiving Asuna's E-Mail was anime original content.
Trivia[]
One of YUNA's songs, longing, can be heard on the radio when Ryoutarou is driving Asuna and Suguha to the harbor.
Cordial Chords (2017, OS BD/DVD) - Distant Journey (2019, Alicization BD/DVD Vol.1) - If We Could Walk Together (2020, Alicization WoU BD/DVD Vol.8) - If You Were Here (2019, Alicization BD/DVD Vol.8) - If You Wish It (2020, Alicization WoU BD/DVD Vol.2) - Rainbow Bridge (2014, Extra Edition BD/DVD) - Sugary Days (2015, Season 2 BD/DVD Vol.5) - Sisters' Prayer (2015, Season 2 BD/DVD Vol.9) - The Day After (2013, Season 1 BD/DVD Vol.9) - The Day Before (2012, Season 1 BD/DVD Vol.1)
Girl Meets Gun ~P90 ni tsuite Yoku wakaru Online (PYO)~ (2018, P-90 Airsoft Gun bonus) - Her step, step (2019, ReoNa's Prologue Album) - Minami no Island Online (MIO) (2018, Dengeki Island!) - MZO (2016, Dengeki Splash) - Pitohui, Elsa, and a Fine Day for Handguns (2021, AM.45 Airsoft Gun) - Sugoimizugi Jam (2015, Dengeki Girls Swim Wear Festival) - The Untold Tale of the Vorpal Bunny's Birth ~Otherwise Known as the Worries of Two Gun Nuts~ (2020, Vorpal Bunny Airsoft Gun bonus)
Idle Talk - The Shinobi's Reckless Remarks (2017, Dengeki Bunko Magazine Animate bonus) - The Story of the Matchmaking Bakeneko (2016, Clover's Regret Vol.1 Animate bonus) - The Strange Tale of Makuwa Melons (2016, Clover's Regret Vol.1 Melonbooks bonus)
Melodies Go Beyond the Forgetting Curve... - The Grand Plan for a Summer Festival Performance! - The Grand Plan to Overcoming Picky-Eating! - When Asuna and Yuuki Changed into Swimsuits (2015)
Ichiban Kuji Ordinal Scale
A Brief Instant of Reminiscing Right Below the Concert - From Asuna's Diary on a Certain Day in Late April (2017)
SAO x KYOTO NIPPON FESTIVAL
The Great Barrier of the Old Capital of Kyoto (2019)