Ouja no Bankuruwase ~Net Shougi no Teiou, Real Taikai de Choujou o Mezasu~

In the world of online shogi, there exists a living legend known as the Emperor of Self-Destruction, a player whose skill makes even the pros shudder. While rumors abound regarding his identity, the truth is far less grand: he's just Mikado Watanabe, a gloomy, socially awkward high school student. After a series of unexpected events leads him to join his school's shougi club, Mikado finds himself entering the Koryu-sen, a prestigious national amateur tournament. As he hones his craft alongside his new teammates, the Emperor of the digital realm begins his ascent toward the throne of the professional world! (Source: Micro Magazine-sha, translated))