, born , was a member of the Japanese imperial family. The Princess was married to Nobuhito, Prince Takamatsu, the third son of Emperor Taishō and Empress Teimei. She was, therefore, a sister-in-law of Emperor Shōwa and an aunt by marriage of the following emperor, Akihito. She was mainly known for philanthropic activities, particularly her patronage of cancer research organizations. At the time of her death, Princess Takamatsu was the oldest member of the Imperial Family.
Early life
Born in Tokyo on 26 December 1911, she was the second daughter of Yoshihisa Tokugawa, a peer, and his wife Princess Mieko of Arisugawa. Her paternal grandfather was Yoshinobu Tokugawa, Japan's last shōgun. Her maternal grandfather, Prince Takehito Arisugawa, was the seventh head of the Arisugawa-no-miya, one of the four shinnōke or collateral branches of the Imperial Family during the Edo period entitled to provide a successor to the throne in default of a direct heir. Lady Kikuko Tokugawa received her primary and secondary education at the then-girls' department of the Gakushuin. At age eighteen, she became engaged to Prince Takamatsu, who was then third-in-line to the Chrysanthemum Throne. By virtue of her descent from the Arisugawa-no-miya, Lady Kikuko and Prince Takamatsu were related. Both were direct descendants of Emperor Reigen, making them sixth cousins twice removed. Prince Takamatsu was a seven-times great-grandchild of the Reigen Emperor, while Lady Kikuko was a five-times great-grandchild of Reigen.
Marriage
thumb|220px|upright|left|Wedding of Nobuhito, Prince Takamatsu and Kikuko Tokugawa (4 February 1930)
thumb|upright|right|Prince and Princess Takamatsu, c. 1950
On 4 February 1930, she married Prince Takamatsu at the Tokyo Imperial Palace. The couple had no children. Shortly after the wedding, Prince and Princess Takamatsu embarked upon a world tour, partly to return the courtesies shown to them by King George V of the United Kingdom in sending a mission to Tokyo to present Emperor Shōwa with the Order of the Garter. During their journey, they travelled across the United States so as to strengthen the goodwill and understanding between their nations. The 1930 photo illustration comes from the illustrated biography on Prince Iesato Tokugawa titled The Art of Peace. The photo presents Princess and Prince Takamatsu during their reception by U.S. President Herbert Hoover.
The Prince and Princess returned to Japan in June 1931 and took up residence in Takanawa in Minato, Tokyo.
Following her mother's death from bowel cancer in 1933, Princess Takamatsu became a champion of cancer research. Using money donated by the public, she established the Princess Takamatsu Cancer Research Fund in 1968, organizing symposia and awarding scientists for groundbreaking work. In an article she wrote for the January/February 2002 issue of a women's magazine, she argued that having a female emperor was "not unnatural" since women had assumed the throne in the past, most recently in the early nineteenth century.
Princess Takamatsu died of sepsis at St. Luke's Medical Center in Tokyo on 18 December 2004,