Saikyou Ranking ga Aru Isekai ni Seitotachi to Shuudan Teni Shita Koukou Kyoushi no Ore, Mob kara Kensei e to Nariagaru

High school teacher Shigeto Kusunoki is transported along with his students to another world where everyone is placed on a "Divine Ranking". While his students gain overpowered abilities, Shigeto’s meager skills land him at the very bottom, completely flipping their usual power dynamic! Thus, with nothing but a single sword, he begins his journey from the bottom as an unassuming schoolteacher to an unrivalled swordmaster!

(Source: Manga UP!)