When humanity was oppressed by mysterious foes known as the Celestial Hosts, five exceptional mages joined forces to defeat them. In fear that these formidable enemies would return, the five most powerful mages, the Magia Vander, built a magical dome and a tower to contain them. Since then, the five strongest mages of every generation have been tasked with monitoring the dome from the top of the Wizard's Tower.

Inspired by this story, childhood friends Will Serfort and Elfaria Albis Serfort promised each other that they would climb to the Wizard's Tower. However, now a sixth-year student at Regarden Magic Academy, Will's future looks bleak. Although Elfaria managed to join the ranks of the Magia Vander five years prior thanks to her unparalleled magical power, Will has no magical abilities whatsoever, attracting the ire of teachers and students alike.

However, blessed with an exceptional physique, Will can slay monsters in the labyrinth and prevail against skilled magicians with the only aid of his sword and a few magical items. Determined to climb the Wizard's Tower at all costs, Will is determined not to let anyone or anything prevent him from keeping the promise he made to Elfaria.