Before a decisive battle, the strongest Demon King Leonis sealed himself away and 1000 years later finds himself reverted to a 10-year-old boy! Rescued by a girl Riselia at Excalibur Academy, Leonis is shocked by the drastically changing world with the unknown enemy Void, Strategic City No. 07 and Demon Sword. In a future world where magic was lost, the curtain rises on a school sword-fantasy.
Before a decisive battle, the strongest Demon King Leonis sealed himself away and 1000 years later finds himself reverted to a 10-year-old boy! Rescued by a girl Riselia at Excalibur Academy, Leonis is shocked by the drastically changing world with the unknown enemy Void, Strategic City No. 07 and Demon Sword. In a future world where magic was lost, the curtain rises on a school sword-fantasy.
