Originally he was named Mototsuna and given to Ōta Hidetsuna but later his childless half-brother Kobayakawa Takakage took him as his adopted son.

He married Ōtomo Sōrin's daughter Maxentia (Katsurahime) and converted to Catholic Christianity with the baptized name Simao Findenao (シマオ・フィンデナオ).

After the Sekigahara Campaign, Hidekane changed his family name back to Mōri, to avoid shame caused by his stepbrother Kobayakawa Hideaki.

Hidekane was known of his gunnery skill, and Tachibana Muneshige's sworn brother.

Together with him and other Toyotomi loyalists, Hidekane participated in Siege of Ōtsu Castle.