Emperor Toba
After taking the time to look through Atsumori's belongings, he found a certain flute, known as the "Saeda" ("Little Branch"). Discovering that the flute was given to Taira no Tadamori by Emperor Toba, and later passed down to Atsumori, he reportedly felt even more sadness and regret for his actions. That morning, Kumagai had heard someone playing the flute with skill outside the enemy camp, and he now realized that that flute player may have been Atsumori.