Three months after LLENN won second place in the team battle, “Second Squad Jam” (SJ2), “Third Squad Jam” (SJ3), was announced. Soon after, news broke out that Pitohui, M, Fukaziroh, and LLENN formed “LPFM,” considered the strongest team in the game. Clarence is obsessed with LLENN, and Shirley ignites her fighting spirit to kill Pitohui. All members of SHINC hope to take revenge as they lost to LLENN in SJ1. A heated battle surpassing SJ2 is about to begin…!

SJ3 has finally begun. The battlefield is located on an island surrounded by the sea. The word "UNKNOWN" is written on a small hill in the middle of the island. "Is this 'UNKNOWN' the 'special rule' for this battle?"

LPFM managed to defeat many members of the allied enemy team, but the island continued to sink, drastically decreasing the physical space they could move around in. LLENN and her comrades avoid areas near the sea and whip up a plan to cut across the northeast section of the island where members of the allied team have gathered. Clarence joins the allied team at this time. She suggests splitting the team into smaller groups of two people and launching waves of attacks against LPFM. However, immediately after they launch this plan, she betrays her teammates and attacks them. In addition, Shirley, who left the KKHC to fight alone, begins joining in on the attacks against the allied team!

Clarence and Shirley defeat and destroy the allied team. KKHC is wiped out after the two kill each other in a fierce battle. Meanwhile, LPFM rides a truck inside a freight car and calmly heads over to UNKNOWN as if going through a deserted field.

The organizing team of the game announced a shocking, special rule to be implemented. One “betrayer” will be selected from the six remaining teams to form a new team. Pitohui is selected from LPFM, and the team leader of SHINC, Eva, also joins. With this new rule implemented, Pitohui is happy that she can fight against LLENN. Eva gracefully leaves her team, hoping to fight against LLENN, too. All of the "betrayers" meet up on a luxury cruise ship set up in UNKNOWN, forming a most intimidating team named "BTRY"!

LLENN and her comrades head to the center of the island, where they find the luxury cruise ship. As the island continues to sink, they must get on board. However, they can’t carelessly approach the vessel as BTRY awaits them onboard.

By Pitohui's orders, the luxury cruise ship continued sailing without stopping its leak, but it began sinking into the water as a result. After a fierce battle, LPFM manages to annihilate SHINC. Meanwhile, Pitohui's trap wipes out MMTM.

It turns out the true "betrayer" from LPFM was LLENN. Pitohui lied, saying she was the betrayer to fight LLENN with all her power. LLENN becomes outraged as she learns the truth and declares she wants to defeat Pitohui.

A month has passed since the fierce SJ3 battles. Karen returns to Hokkaido and tells Miyu she can’t decide whether to continue playing GGO. However, Miyu figures out that Karen's actually concerned about the pure rivalry with Elza and Saki.

LLENN decides to participate in the game to battle Eva of SHINC with all her might. To clear the game, a player must destroy all seven NPCs or take back the gas bombs they stole. LLENN and LPFM members head to the location where the enemy awaits. They encounter SHINC along the way. As they're about to attack, ZEMAL attacks them first. ZEMAL's attack proved too much as their "backpack style ammunition carriage system" allowed them to fire rapidly without any breaks, leaving LLENN and LPFM clueless on how to counterattack.

NPCs barricade themselves in a castle and easily wipe out MMTM and SHINC with power beyond anybody's imagination. ZEMAL subsequently tries to enter the castle with a sign that says, "We’re not your enemy; let us into the castle!" They fail as Pitohui sabotages them. LPFM's drone, considered the jewel in their operations, gets shot down by NPC attacks. Pitohui suggests everyone from the other teams cooperate in a coordinated attack. They attack the castle with T-S, ZEMAL, MMTM, and SHINC!