However, because he felt that he did not receive a fair amount of reward grants, Takatomo was dissatisfied, and in 1387, along with the rebellion of Wakainumaru OYAMA, he opposed against Ujimitsu.
ところがそれに対して鎌倉公方・足利氏満の恩賞が不当に少なかったため、孝朝は不満を抱き、1387年の小山若犬丸の反乱に乗じて氏満に反乱を起こした。