Legendary Hero Is an Academy Honors Student

Alternative:

転生した英雄はアカデミーの優等生 / 전설급 영웅은 아카데미 우등생

In the Age of Catastrophe, five heroes saved the world from a primordial evil. One of the heroes, now reborn as Leo Plove, is excited to revisit his glorious past—only to find his name erased from history. Determined to uncover the truth, he joins Lumerne, a hero military academy, unaware he’s about to discover dark secrets surrounding his reincarnation. Why are his records hidden, and who wants to keep them that way? Will Leo be able to set things right and reclaim the credit he deserves?