Dungeon Gakuen no Teihen ni Tensei Shita kedo, Naze ka Ore ni wa Kouryaku Hon ga Aru

Takashi Takasugi was never meant to be a hero. According to the official strategy guide of a popular game, he was merely the lowest-ranked student in his class—a perpetually unlucky background character destined to clash with the protagonist, drop out of the academy, and ultimately meet a rumored demise. Yet, in a cruel twist of fate, a player from the real world suddenly finds himself reincarnated into the body of this doomed, bottom-tier nobody. Overwhelmed by despair over his tragic predetermined future, he frantically searches his classroom desk and makes an unbelievable discovery: the very same strategy guide he purchased in his previous life has materialized alongside him. Realizing that this comprehensive manual holds the key to altering his grim destiny, he resolves to use its hidden knowledge to secretly grind his skills within the academy's dungeons and become the strongest. However, his path to survival is fraught with relentless hardship at every turn. It is only when he unexpectedly begins traveling alongside the game's beautiful heroine, Hanagasaki, that his seemingly cursed fate finally takes a dramatic and hopeful turn.