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

"Takashi Takasugi is the lowest-ranked student in his class, plagued by bad luck. He clashes with the protagonist, leaves the academy, and is rumored to have died—a truly unfortunate character."

That's how the game's strategy guide described him... and now, the protagonist finds himself reincarnated as this bottom-tier nobody!

Drowning in despair, he searches his classroom desk—only to discover the very strategy guide he bought in his previous life. "If I use this, I can become the strongest!?" Determined to escape his tragic fate, Takasugi sets off to secretly grind his skills in dungeons... but hardship awaits at every turn. However, when he starts traveling alongside the game's beautiful heroine, Hanagasaki, his destiny takes a dramatic turn!

(Source: Bunkasha, translated)