Background
Koretoyo Aso was born in Japan. He was a son of Korenori.
Koretoyo Aso was born in Japan. He was a son of Korenori.
Koresaki, Korenaga' s son, carried out a surprise attack on him when he was at Katashida Castle in Masuda County, intending to annex his fief. Unable to defend the castle, he fled to Mt. Kuraoka in Hiuga Province (Miyazaki Prefecture). Afterward, with the support of Chikanobu Kai, Koretoyo defeated Koresaki and recovered his position.