text: After losing all but five participating soldiers in an attack, this ruler pulled a night ambush with the help of Okubo Tadayo to survive the Battle of Mikatagahara.
full_question: After losing all but five participating soldiers in an attack, this ruler pulled a night ambush with the help of Okubo Tadayo to survive the Battle of Mikatagahara. His father allowed him to be killed to prove his father’s allegiance to Imagawa. This ally of Oda Nobunaga defeated the forces of Ishida Mitsunari in the Battle of Sekigahara. For 10 points---name this founder of Japan's final shogunate
first_sentence: After losing all but five participating soldiers in an attack, this ruler pulled a night ambush with the help of Okubo Tadayo to survive the Battle of Mikatagahara.