In the kingdom of Aethelgard, Ethan Vance is the academy's most overlooked student — an F-Rank mage with barely enough mana to light a candle. But hidden beneath his unremarkable surface lies the Resonance Heart, an ancient family relic that rewards genuine acts of teaching with power ten times over. When he reaches out to help Clara Sterling — a fallen duke's brilliant daughter whose wild Lightning magic threatens to consume her — the relic awakens, and so does something neither of them expected. As they train together for the kingdom's Grand Tournament, every breakthrough Clara achieves pulls Ethan closer to the strength he never knew he had, and every quiet moment between them pulls them both toward a truth they're not yet brave enough to name.