If you're looking for manga similar to Nobunaga wo Kuroshita Otoko, you might like these titles.
The most feared / respected legendary warlord Oda Nobunaga, who disappeared from history just as he was about to unify Japan. He was born in war, raised for war, and grew into war. Nobunaga was a true “Child of War”!
The story starts in 1560, before an impressive battle where Nobunaga's forces were severely outnumbered by his enemies, the Imagawa clan. The story then begins to jump back to earlier times in his life, in the 1550s and 1540s. Through this manga, one can learn of Nobunaga's military, political, and personal life, and how he came to shape the history of Japan.
Deadly Sengoku-period samurai Honda Sakuzaemon Shigegetsu, known as Oni Sakuza for his ferocity. He fights for Tokugawa Ieyasu, along with the warrior Ookubo Hikozaemon Tadataka. Tokugawa's forces, along with the forces of Toyotomi Hideyoshi are attacking the last independent daimyo, Hojo Ujimasa, who ruled 8 provinces in the eastern Kanto region of Japan. Sakuza is still suspicious of this new ally, and still considers anyone not Tokugawa an enemy!