Tatsumiyajima is the central island in the middle of a small cluster of islands, in a sleepy backwater of the Japanese isles. Not much happens there, and the island's young people go to school knowing that their lives are likely to remain peaceful and undisturbed. Or so they have been taught...but the truth is different. The fate of mankind is on the line, and Tatsumiyajima is the last line of defense against a hostile and incomprehensible enemy. At the center of it all, fighting for Humanity's continued existence, is the giant robot Fafner, the dragon that guards this final treasure of mankind.

Kaede Honjou is invited by her friend Risa Shiramine to play a virtual reality MMO game with her. While Kaede doesn't dislike games, what she really, truly dislikes is being in pain. She creates a character named Maple, and decides to put all her points in VIT to minimize pain. As a result, she moves slowly, can't use magic, and even a rabbit can get the best of her. But as it turns out, she acquires a skill known as "Absolute Defense" as a result of her pumping points into VIT, as well as a "Counter Skill" that works against special moves. Now, with her ability to nullify all damage, she goes on adventures.

The story takes place several years after Lelouch's "Zero Requiem" plan. He gave up his life to save the world and protect the ones he loved. The day Lelouch vi Brittannia fell was the day this war-torn world found peace. Now, as his friends work to keep the peace, a terrorist attack could risk everything. Can the brilliant tactician outwit death and save them all? Or will Lelouch’s legacy fall here?