Birth and death dates unknown. Son of Toki Tameyori, lord of Mangi Castle. His father switched from the Satomi to the Later Hojo around the 1564 Second Battle of Konodai. Yoriharu inherited the headship in 1579. From 1588-1590 he repelled three Satomi assaults known as the Battles of Mangi and Chonan, building the clan's largest domain. But his Hojo alliance proved fatal in 1590: Mangi Castle fell to Honda Tadakatsu's forces, and Yoriharu vanished from the record after his defeat, possibly by suicide, ending the Kazusa Toki clan.

His repeated success against Satomi assaults suggests a skilled field commander, though his continued Hojo alliance during the Siege of Odawara proved a fatal misjudgment.

The ruins of Mangi Castle are preserved as a historic site in Isumi City, where scorched rice from the castle's fall has been excavated near the presumed storehouse site.