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