Demon's Sword Master of Excalibur SchoolSeiken Gakuin no Maken Tsukai; 聖剣学院の魔剣使い; The Demon Sword Master of Excalibur Academy; 圣剑学院的魔剑使; 圣劍學院的魔劍使; Мастер демонического клинка из академии «Святого Меча»; Ma Kiếm Sư Tại Học Viện Thánh Kiếm

In the fantasy story, the demon king Leonis sealed himself away for 1,000 years in order to prepare for the final battle, but when he woke up, he found himself in the body of a 10-year-old boy. A beautiful young woman named Lisellia from the Holy Sword Academy then says to him, "Why were you locked up in such a place? It's OK now, this big sister will take care of you!" Under Lisellia's care, Leonis is shocked to see that the world has completely changed. Bewildered and confused, Leonis finds himself enrolling at the Holy Sword Academy.