The Demon Swordsman of the Holy Sword Academy

Leonis, the Demon King of the Undead, sealed his soul for the decisive battle that will come in the future. However, when he woke up again 1,000 years later, for some reason he turned into a 10-year-old boy! ? Leonis, who was protected by the beautiful girl Lyselia who belonged to the "Holy Sword Academy", enrolled in the "Holy Sword Academy" without knowing anything about this completely different world. The unknown enemy 〈Void〉, 〈07th Tactics City〉, and the 〈Holy Sword〉 which looks like a weapon but possesses supernatural powers. In this future world where magic has been forgotten, the school fantasy story of holy swords and magic swords intertwined by the strongest demon king and beautiful girls opens grandly!