It's been six months since Shiroe and the other adventurers have been trapped in "Elder Tale". As Akihabara moves into late fall, the city is excited for the cultural fair. But Shiroe is ignoring the fun and speaking in secret to a land person, Kinjou, who controls the world's currency flows. When negotiations are over he tells his friend's leaving the city. The long-awaited second series of "Log Horizon" begins a new adventure!

Shiroe, Naotsugu, and Regan head to the northern city of Susukino, which was once run by the evil and violent Briganitia guild. They're looking for high-level adventurer's to help them get the the "Sacrifice Clan's Gold". Shiroe visits an unexpected person. Meanwhile, Naotsugu and Regan walk through the frozen town and find a small but pretty girl named Tetra. She calls herself a "galactic idol", and she's very irritating, but her level is 92...!?

Shiroe and his friends have come to the Depths of Palm to reach the Sacrifice Clan's gold. The underground labyrinth is filled with powerful monsters that wear them down in a war of attrition. Meanwhile, Akihabara, Akatsuki hears about the "Teachings". She's very interested to know that by completing a high level raid, she can greatly improve the level of her techniques.

It's almost Christmas in Akihabara. At Lenessia's mansion, Marie and Henriette are all visiting. Lenessia is smiling, but she can't open herself up to the adventurers because of how different they are. Akatsuki, who has been tasked with guarding the princess, is the only one who isn't having fun. She thinks of Shiroe and worries about her own powerlessness. Then, in Akihabara in December, a shocking event occurs.

A man appears in Akihabara and begins killing adventurers with powerful Royal Guard equipment. Lenessia is shocked to learn that he is one of the Land people, of the Kunie clan. Akatsuki goes to put a stop to him herself, as the West Wind Brigade scouts find him...

Akatsuki is defeated by the murderer on Christmas Eve. She awakens to find herself in bustling Shibuya station in the real world. She wanders through the city as if escaping from something, and then appears on a quiet beach. Shiroe is there.

Akatsuki revives at the Cathedral and asks the others for help to defeated the murderer. She trains with the top members of D.D.D. and the West Wind Brigade in an attempt to learn the Teachings.

A full raid of 24 party members has been formed to defeat Nerelith! The maidens gather to defend Akihabara! Meanwhile, Lenessia and Henrietta head beneath the Guild Building for a certain mission...

On Christmas Eve, Shiroe and the other members are fighting the level 97 boss monster "Luseat of the Seventh Garden." But two more boss monsters appear in the middle of the battle, and they are overwhelmed. Shiroe is caught in the fires of "Ibrahabra of the Third Garden"...

William, the leader of the combat guild Silver Sword, faces a great crisis as his guild has been defeated and is thinking of going home and quitting. He gives an inspiring speech to rally them into the fight once more.

With honesty and renewed sense of comradery the team has a small chance of winning an unbeatable raid.

The final boss, Uru of the Ninth Garden vs the villain in glasses, Shiroe is up against what could be the strongest boss in this new world.

It's February 14th! Akihabara is filled with excitement as the adventurers enjoy their first Valentine's Day. Marielle and Isuzu try to make cookies out of Kokonia fruits, which are said to make someone fall in love with you. Meanwhile, in the Log Horizon guild house, Tetra puts Akatsuki and Minori up to cooking something for Shiroe.

When Elder Tale was a game, there were talented solo players who would come together whenever they felt like it and defeat difficult raids. Their name was "The Debauchery Tea Party." Now, their leader, the cheerful girl Kanami, is traveling through the vast lands of the Chinese server on her way towards Yamato.

As spring comes to Akihabara, Shiroe decides to send Minori, Touya, Isuzu, Rundelhaus, and Serara on a quest to get the magic bag, a convenient and critical item for high-level adventurers. The 5 excitedly put together their things and get ready to go on a journey.

The gang sets out towards the redstone mountains to get their magic bags. On the way, they meet a party of merchants who are being attacked by monsters. They save the merchants but are overwhelmed, when a girl who looks just like Shiroe saves them.

Continuing on their way to the Redstone mountains, the gang encounters a mysterious group: the Odyssey knights, a group of players who'll do anything to get back home. Their eyes are strangely lifeless, and they're carrying a strange altar that allows its users to ressurect immediately.

Dareila joins the party at the Boxurt mountains, and the group stops at the town of Saphir. Isuzu learns that the reason the land people enjoy her songs so much is because the world only has 42 songs in total. She gets very sad and stays in her room, but then a giant flock of wyverns descend upon the town.

A massive flock of wyverns suddenly attacks the town of Saphir! The party tries their best to protect the town, but the Odyssey knights are constantly flinging themselves to their deaths. Meanwhile, Roe-2 looks at the brutal combat and doesn't even blink an eye...

A Minami plot was behind the massive wyvern attack on Saphir. To stop the plot, Nyanta attacks the train carrying the Minami general alone. But he's faced with the sorcerer he defeated long ago, the man who trapped Serara in the far north, Londark.

Operation "Red Night" is canceled and the kids come home to a joyous reunion. They've gotten their magic bags and succeeded in their quest. But a strange man is going around Akihabara asking all the girls to marry him.

Shiroe receives a letter from his second character on the lunar test server. As the situation in Akihabara deteriorates, it offers him hope.

Isaac and the Black Sword Knights are responsible for training the Maihama army. While he's in Maihama Isaac gets to know the new crown prince of Maihama, a young boy named Iselus. Iselus respect looks up to Isaac and respects him. At a party for the crown prince's birthday, assassin's make an attempt on his life.

At moonrise, the player cities of Akihabara, Susukino and Minami are all simultaneously attacked by swarms of Eternal Moth monsters, whose scales rain down and knock people into a state of sleep by draining their magic points. The Brigade of the West Wind soon discover the moths' nest located in a new raid zone in the Shibuya broadcast building and the Round Table postulate that the monsters had been drawn to the broadcasting antenna from the Moon. Filled with uncertainty, Shiroe decides to put together a raiding party and makes the difficult choice of destroying the antenna. The raiding party then fights their way through Shibuya and manage to enter the raid zone in the broadcast building. However Shiroe's uncertainty hinders his strategic insight and allows the sheer volume of monsters to overwhelm the party from all angles, forcing them to make a hasty retreat.

The Shibuya raiding party begins another assault on the Calling Fortress and manage to break through to the roof where they encounter the raid boss: Taliktan, the Genius of Summoning. After failing to establish communication with the monster, it summons swarms of moths which engulf Shibuya and the other player cities. This puts a severe strain on the antenna and Shiroe has the party take the battle into the concert hall below. Despite inflicting a great amount of damage to Taliktan, they are still pummeled by its powerful field attacks. However Shiroe's Full-Control Encounter raises the stakes and gives the party a significant advantage in pushing Taliktan to the edge and ultimately their victory. In the aftermath, Regan sets up the radio equipment and much everyone's surprise, Shiroe makes contact with Kanami in the Chinese server. She then tasks him with seeking a way to allow transit between the real and Elder Tale worlds and relieves the Shibuya party about Krusty's whereabouts. Meanwhile, Nureha and Plant Hwyaden decide to establish relations with Eastal and the Round Table to combat the common Genius threat. Finally, Log Horizon makes plans to celebrate their victory and with the dawn over the horizon, Shiroe and Akatsuki praise each other. In the epilogue, Log Horizon holds a victory party and Regan skips out on his task with repairing the radio equipment to join the festivities.