A single solar eclipse stole everything.
One moment, Kazuki Ito was an ordinary boy from Earth. The next, he awakens in Aerith—a world ruled by mana, noble families, and monsters born from shadows.
There is no way home. No one waiting for him. Worse, Aerith's ranking system labels him the weakest existence possible: Index VII.
Then a pitch-black interface appears.
The Eclipse System.
It offers no comfort, no mercy, and no easy power. Instead, it forces Kazuki through brutal lessons where survival itself is the reward.
Friends die. Hope fades. Every lesson demands another sacrifice.
Yet Kazuki keeps walking.
Searching for a way to repair his broken phone—the only connection he has to Earth—Kazuki begins uncovering impossible truths. Familiar names. Familiar faces. A twenty-year-old eclipse. And a mystery connected to his arrival.
Earth, Aerith, the Eclipse System... none of it was an accident.
Some people are chosen to become heroes.
Kazuki was chosen to become a lesson.