Oyu (Oichi) was the sister of the infamous Nobunaga Oda, and the wife of Nagamasa Azai until the latter's death. She never met Jubei but did join in the fight against her overlord brother, historically with her husband - Azai Nagamasa rather than Jubei, but she later joined Toyotomi Hideyoshi.
Onimusha 2: Samurai's DestinyEdit
In the game, she is first seen by Jubei in the town of Imasho. Later he finds her in the clutches of Tokichiro (the future Toyotomi Hideyoshi) and rescues her (however her daughter Yodo will later go on to becomes his concubine and the mother of his heir), in fact joining the fight in order to secure her husband's territory. She Oyu then assists Jubei in his battles against her brother's armies. Over the course of the game she begins to fall for Jubei, and when both she and him are trapped by Tokichiro, she reveals to Jubei that she is Nobunaga's sister. Oyu then goes on to explain her reason for being caught at Gifu Castle: she planned on assassinating Nobunaga, due to his malicious intentions of destroying the Azai clan and conquering Odani. Oyu also reveals to Jubei that she felt betrayed when she learnt from Nagamasa, 2 years after they were married that he has 3 daughters from his previous marriage.
She then tells him that nothing mattered to her after that until she met Jubei. Oyu then thinks of herself to be selfish because of her statement and becomes set on returning to Odani in order to protect her daughters. Jubei and Oyu soon wipe out Nobunaga's armies at near Odani Castle, and then head for Gifu Castle where her brother is at. Following a quick reunion between Jubei and Oyu, Jubei then convinces her not join him on his final battle against Nobunaga, reminding her that he is still her brother and cannot be involved. They then finally share a memorable kiss before he departs to face Nobunaga.