A warrior of the late Kamakura and Northern and Southern Courts period, born a powerful chieftain of Kawachi Province. In 1331, at the Genkō Incident, he raised arms in response to Emperor Go-Daigo's call to overthrow the shogunate. Holing up in mountain castles such as Chihaya and Akasaka, he employed guerrilla tactics against the overwhelming shogunate forces, fanning the momentum for the regime's collapse. Under the Kenmu Restoration he was deeply trusted by the emperor, but the defection of Ashikaga Takauji reversed the situation. At the Battle of Minatogawa in 1336, fully aware of his impossible position, he refused to retreat and died in a fierce last stand alongside his brother Masasue, at the age of 43. His parting words—"seven lives for my country" (shichishō hōkoku)—were passed down as a symbol of loyal devotion. In the Meiji era he was celebrated as Dai Nankō, and statues were erected throughout Japan.

A commander who combined profound loyalty with cool strategic intelligence. Never despairing under adversity, he outmaneuvered larger forces with unorthodox tactics. His death at Minatogawa exemplified an unwavering commitment to his lord even in the face of certain defeat.

He exerted immense influence on later generations as a symbol of loyal devotion. In the Meiji, Taishō, and Shōwa eras, he was a national hero embodying "loyalty and patriotism," and is enshrined at Minatogawa Shrine in Kōbe. The ruins of Chihaya Castle are a designated national historic site.