The guild leader, Keita, extended an invitation to Kirito after he learned that he was a solo player. Hiding his true level, Kirito joined as a temporary member until the guild could be independent without him. Kirito was also asked to help with the stat development of another player named Sachi. A month later, Kirito and the guild were seen training in the Sunshine Forest on the 20th Floor, where Kirito assisted the guild in taking down a Killer Mantis.
To maintain his own level, Kirito kept sneaking out at night to go grind in the higher floor Labyrinths. After coming back from his self-leveling, he received a message from Keita, saying that Sachi had gone missing and that they were looking for her in the Labyrinth. He quickly found her within the drains of the city with the help of his «Tracking» skill. After learning that she was incredibly afraid of dying, Kirito tried his best to reassure her, constantly telling her that he would not let her die. Afterwards Kirito would commonly comfort Sachi whenever she was afraid, thus helping her sleep by being by her side.
Less than a month later, when the group finally collected 20,000 Cor, which was enough to purchase a guild home, Keita teleported to the Town of Beginnings to purchase a new base for the guild. While Keita was gone to buy the house, the other members decided to impress him by getting items from the labyrinths near the front lines. Kirito tried to object, but the members insisted they were strong enough. The group, excluding Keita, traveled to the 27th Floor Labyrinth, where they found a hidden door after finishing their hunting quota. Ducker, the guild's thief, picked the lock and found a treasure chest in the room. Kirito quickly recognized it as a trap, but he was too late, as the guild members had already opened the chest. The room suddenly turned red and a swarm of monsters surrounded them. The group's teleport crystals failed to activate; the trap was an Anti-Crystal Area with the only exit being sealed. Kirito tried to defend himself and reach Sachi while witnessing the other members fall one by one due to their low levels. Despite Kirito's effort to protect her, Sachi was killed as well. She had said something right before turning into polygons, but Kirito did not hear what she said due to the crisis.
Several months later, on December 24, 2023, Kirito met with the information broker Argo the Rat, questioning her about the location of the Christmas event boss. Obsessed about the possibility of a revival item said to be in possession of said boss, Kirito hoped to hear Sachi's last words. It did not matter to him whether she hated him or not, he would take all her anger. As it was nearly time for Christmas Eve, Kirito changed into better equipment while lamenting the death of his fellows. A flashback occurs where, Kirito informed Keita about the demise of the other members, and told him that he had known about the possible trap since he was at a higher level due to being a «Beater»; Keita cursed him and leaped off the Aincrad's edge into the endless sky.
Kirito then headed off to a 35th Floor dungeon, the Forest of Wandering. Along the way, Kirito was followed by Klein and his guild, Fuurinkazan. Klein initially wanted to fight alongside with Kirito against the Christmas boss, but Kirito refused. As Klein tried to convince his friend, another guild, the Divine Dragon Alliance, appeared near their location. Klein and his guild members decided to hold off the opposing guild while Kirito handled the boss, Nicholas The Renegade.
While Klein and his fellows rested from their fight, a halfhearted Kirito appeared before them. Klein asked what was wrong and Kirito handed him the the revival item, the «Divine Stone of Returning Soul». After reading the item's description, Klein found out that it could only save a player during their ten-second «End Phase». As Kirito started walking off into the distance, Klein stopped him and requested he live on till the end.
Kirito then headed back to his home and sulked in front of his desk while waiting for morning. Suddenly, Kirito was alerted by an incoming message in his inventory. To his surprise, he had received a recorded message from Sachi that was timed to appear at Christmas Day. After engaging the message record crystal, Kirito listened to the sound of Sachi's voice, telling him although she would probably be dead at that point, her death was not his fault. She mused on how her death was inevitable, and asked Kirito to fulfill her wishes. She ended the message by humming "Rudolph the Red-Nosed Reindeer" and thanking Kirito for all the time he had spent with her.
- Lava Plate
- Rubber Plate
- Metal Plate
- Chestguard of Silver
- Cardboard Armor
- Breastplate of Steel
- Guard Suit
- Silver Armor
- Silver Plate
- Metal Boots
- Black Boots
- Blade of Frost Steel
- Munin's Talon
- Timer-Activated Message Record Crystal - Received from Sachi
- Divine Stone of Returning Soul - Received from Kirito
- Teleport Crystal
- Aincrad Floor 11: Taft
- Aincrad Floor 20: Sunshine Forest
- Aincrad Floor 27: Labyrinth
- Aincrad Floor 28: Wolf Plains
- Aincrad Floor 35: Forest of Wandering
- Aincrad Floor 49: Myujen
- Adapted from Volume 2, Red-Nosed Reindeer.
- The anime did not show that Klein met Kirito while he was training and that they talked about the Christmas event.
- In the anime, Klein and his group were shown fighting off a group of Blood Wolf Leaders on the 28th Floor before the death of the Moonlit Black Cats, whereas in the novel they were training against an ant-like monster on the 46th Floor just five days away from the Christmas event.
- Argo does not make an appearance in the light novel, but was mentioned by Klein during their conversation.
- The initial story of how Kirito met up with the Black Cats is not portrayed in the anime.
- In the novel, Sachi was using a cloak that granted invisibility when Kirito found her.
- There was no mention of the shared inventory window between Kirito and Sachi in the anime.
- In the light novel, it was stated that Klein negotiated with the Divine Dragon Alliance to have a 1-on-1 duel between him and a member of the Alliance to decide their next course of action. Because of this, only Klein was tired after the match, but in the anime it looks as if everyone in the Fuurinkazan guild fought against the DDA guild.
- In the anime, it was not revealed how Kirito got out of the trap alive. In the light novel, Kirito destroyed the treasure chest, thus disabling the trap.
- In the light novel, Sachi left the message record crystal in a shared inventory tab between her and Kirito with the timer-activation mode active, instead of a time-triggered mail.
- In the light novel, Sachi actually sang the "Rudolph the Red-Nosed Reindeer", instead of humming it.
- Sachi did not mention a friend of hers that died on the way back to town in her message to Kirito in the anime.
- In the anime, the members of the Black Cats died on the 12th of June, while in The Day After it is revealed that they actually died on the 22nd of June.
- "Willpower is what separates us from the clearers; the determination to protect one's friends.... no, everyone. Right now, they are still protecting us." - Keita
- "In this world, the dead won't return." - Kirito
- "Kirito... Kirito! You have to survive. Survive until the end please..." - Klein
- "Even if I die, you keep living okay? Live to see the end of this world, and to see why it was born. Live to see why a weak girl like me ended up here... And the reason you and I met." - Sachi
- Although in the anime it is not mentioned, Nicholas actually dropped a whole bag of loot. The Divine Stone of Returning Soul was only one of the dropped rewards.