18+ Eiyuu Kyoushitsu

After defeating the Demon Lord, the great hero Blade finds himself on the brink of death. Though he miraculously survives, he loses a significant portion of his strength. Being stripped of his immense power frees Blade from the obligation of being humanity's savior. He chooses to spend his newfound freetime embarking on a new quest, making friends.

Blade enrolls at Rosewood Academy, an institution that trains prospective heroes to become bonafide champions of justice. He quickly fits in, befriending his fellow classmates and helping them through the trials and tribulations on the path toward becoming a hero.