She was born in about 1546, the daughter of Sugihara Sadatoshi. In about 1561, she married Toyotomi Hideyoshi, a man who would later become one of the three great unifiers of Japan. Nene was one of his favorite wives. It was a successful marriage, despite it being arranged and the fact that the couple were childless.
In 1585, after Hideyoshi appinted to the post of Kampaku, Nene took on the title of "Kita no mandokoro", by which she is most commonly known by in English.
As the wife of Hideyoshi, Nene is most famous for being one of his closest aides and confidantes. Because she was the daughter of a samurai, she had many familial connections that netted Hideyoshi several retainers. Among these retainers were Sugihara Ietsugu (Nene's uncle), Kinoshita Iesada (Nene's brother), and Asano Nagamasa (Nene's brother-in-law). The last of these characters would serve as an important official in Hideyoshi's later administration.
Although Nene did not produce any children for Hideyoshi, she was known to have been an intelligent woman who, at times, advised Hideyoshi on matters of governance by sending him letters. When Hideyoshi gained a large fief in Ōmi Province following the defeat of the Azai and Asakura clans, he exempted the residents living in his headquarters at Nagahama from paying taxes, but afterwards reneged on giving his citizens special tax privileges. Nene, however, protested Hideyoshi's second decision and, as a result, Hideyoshi later repealed it and extended tax benefits to his civilians again. On other occasions, Nene probably gave Hideyoshi advice on civil affairs as well. It is also recorded that Hideyoshi frequently wrote letters to Nene to tell her about how his campaigns were going. Hideyoshi did this after his invasion of Sassa Narimasa's territory in Japan's Hokuriku region and after his campaign against the Shimazu clan, and probably during other times in his career.
When Hideyoshi unified Japan, Nene often went with him to attend parties. Nene was courteous and respectful to her guests on every occasion. and when the Emperor of Japan, Go-Yozei, came to Hideyoshi's Kyotite mansion with his entourage in 1588, Nene freely distributed a plethora of gifts to Hideyoshi's visitors. Nene worried about Hideyoshi often when he was on his deathbed. Eventually, as Hideyoshi was on his last throes, she even petitioned the Imperial Court to sponsor a sacred dance ritual to pray for and expedite Hideyoshi's recovery.
Though adored, Nene often found herself competing with other women for Hideyoshi's attention. In a letter to Nene, Oda Nobunaga also noted that Hideyoshi was somewhat dissatisfied with Nene. Whilst the love between Nene and Hideyoshi was probably reciprocal, Hideyoshi still took up several concubines for himself because Nene could not bear for him any children.
There are rumors (albeit unconfirmed) that during the Sekigahara campaign, Nene had taken a pro-Tokugawa stance. Other rumors say that before she was married to Hideyoshi, Maeda Toshiie, an Oda and Toyotomi vassal, used to have a crush on her.
After Hideyoshi died in 1598, Nene decided to become a nun. She took the name Kōdai-in(高台院,Kōdai-in?) and established a Buddhist temple, Kōdai-ji in Kyoto, to which she moved. It became the burial area for her husband, his mother, and later Toyotomi Hideyori. During the contest between Toyotomi Hideyori and Tokugawa Ieyasu for supremacy, Nene took the side of Ieyasu.
