Aga Kimi Chiru ran

A high school student with no hope for the future, Fuyumuro Tanka, travels back in time to Ashikaga Academy, the largest educational institution for "gunbai-shi" (military strategists) during the Sengoku period! Control the battlefield with your wits and aim for domination of the world with a single move. A tale of strategic battles where divine calculations and devilish strategies spark off!

(Source: Sunday Webry, translated)