Welcome to Aurora: a medieval world plagued with ever-present lightning. Cities and roads bristle with lightning spires for protection from charged skies. In thunderous, heart-stopping battles, metal shards are catapulted over enemy armies, summoning lightning from the clouds. Plants and creatures have evolved to use electricity for survival-an obsidian humanoid race, the inazuma, feed on lightning. And a few enlightened humans, an order of warrior monks, masters of electrical weaponry and physics, use it to fight and heal. Shotoku is a naïve young warrior in this dangerous world. After killing his own brother, Shotoku vows never again to use his tremendous electromagnetic powers. But on the eve of invasion, as allies turn traitor and danger gnashes from all sides, can he hold his oath pure? Drawn to his virtue, an enemy warrior princess, Makiko, will help him find balance; and, when his principles falter, his roguish friend, Jirai, will deliver salvation. But in the end, only Shotoku can decide: Will he shatter his vow, unleash his chaotic power, and face the invaders alone? Or, by honoring his oath, will he gain the new allies that might help him save the world?