Sengoku Basara Ranse Ranbu

It is a time of civil war, and the young warlords running Japan are... hopelessly stupid. This manga takes place in the Sengoku (Warring States) Period in Japan, and is based off the game Sengoku Basara, otherwise known as Devil Kings in the US. Sanada Yukimura, who serves under his master Takeda Shingen, hopes to accomplish his master's dreams of a united Japan. However, he is faced with many obstacles, forcing him to battle against many powerful warriors with the same ambitions. One of these men is Date Masamune; with his flamboyant attitude and his ideal "fun," he stirs up uncontrollable anxiety within Yukimura that draws him into the heat of battle...

Based on the video game.