A woman of the Sengoku period, born a younger sister of Oda Nobunaga and celebrated as "the greatest beauty of the Sengoku age." Through a political marriage she wed Azai Nagamasa, daimyo of Ōmi Province, and bore him three daughters: Chacha (Yodo-dono), Hatsu, and Gō. When the Azai clan was destroyed in 1573 following the rupture between Nobunaga and Nagamasa, she and her daughters were taken back into the Oda family. After Nobunaga's death in the Honnōji Incident (1582), she joined Shibata Katsuie, whom she married the following year. Defeated by Hashiba Hideyoshi (later Toyotomi Hideyoshi) at the Battle of Shizugatake in 1583, Katsuie retreated to Kitanosho Castle in Echizen. After sending her three daughters out of the castle, Oichi died alongside Katsuie by suicide, at the age of 36. Her eventful life has been depicted repeatedly in later literature and drama as a symbol of tragic womanhood.

A woman of nobility and grace with an inner core of resolve. Though used as a tool of political alliance, she gave deep affection to both her husbands, and her maternal love for her children was unwavering. Her decision to remain by her husband's side to the end expressed the pride of a warrior's wife.

Through her three daughters, she exercised great influence on the Toyotomi and Tokugawa eras. The eldest, Chacha, became Hideyoshi's concubine and bore Toyotomi Hideyori; the youngest, Gō, became the wife of Tokugawa Hidetada and supported the foundation of the Tokugawa shogunal line. The story of the "three Azai sisters" continues to be beloved in modern NHK historical dramas.