Unwilling to engage him in open warfare until he was sure of his strength, Yamana chose to intervene in a number of succession disputes and other political affairs, thwarting Hosokawa's plans and desires, and slowly gaining allies for himself.

[1] In 1466, both sides having spent several years gathering forces, both Yamana and Hosokawa felt ready to engage the other, and skirmishes began to break out.

In 1467, the first year of Ōnin by the Japanese calendar, both men began to prepare more seriously for the coming conflict; they sought safehouses and planned for fighting in the streets.

Seeing that open war in the capital would spread to the provinces, the shōgun declared that the first to make an attack within the city would be labeled a rebel against the shogunate, and enemy of the state.

For much of that year, the two forces engaged in glaring contests and limited sorties, both desiring to rebuild and to act only defensively.

Both spent the next several years in political, not military, conflict, and in 1469, the shōgun named his son Yoshihisa as his heir.