Where Spider Lillies Bloom

The Japanese military has been working with cursed spirits as weapons.

With the assistance of Jujutsu sorcerers, including Megumi Fushiguro, Satoru Gojo, and Suguru Getou, a cursed infection is born. It can overtake living human bodies, defeat the mind, and kill from the inside out. Skin begins to decay within minutes, fevers overwhelm the victims, they have a thirst for human blood, and the original person is gone within an hour. This is the Japanese last resort military weapon.

But it isn't long before it spirals out of control. Within the span of two days, 90% of the Japanese population is infected; the survivors are either Jujutsu sorcerers or lucky citizens. All have lost hope. The sky turns from bright blue to a bloody horizon. And in the middle of it all, Satoru Gojo is also infected. Suguru puts the past aside in a desperate attempt at revival. Tsumiki Fushiguro is infected. Megumi risks his life to protect her.

But this can only last for so long. Eventually, society must end. The question isn't will it, it's when will it. A month? A year? Five years? No matter how you look at it, the Japanese population will be wiped out in the next ten years. Including sorcerers.