Lady Kasuga (春日局 Kasuga no Tsubone?, 1579 – October 26, 1643) was from a prominent Japanese samurai family of the Azuchi–Momoyama and Edo periods. Born Saitō Fuku (斉藤福), she was a daughter of Saitō Toshimitsu (who was a retainer of Akechi Mitsuhide). Her mother's father was Inaba Yoshimichi. Married to Inaba Masanari, she had three sons, including Inaba Masakatsu, and an adopted son, Hotta Masatoshi. She was the wet nurse of the third Tokugawa shogun Iemitsu. She also established the Ōoku, the women's quarters, at Edo Castle.
In 1629, Ofuku traveled to the capital, where she had an audience with the emperor at the Imperial Court in Kyoto. She was promoted to the extraordinarily high Court rank of second class; and after this time, she was called Kasuga-no-Tsubone or Lady Kasuga.
Her grave is in Rinshō-in, a temple in Bunkyō, Tokyo; the temple possesses a portrait of Kasuga by Kanō Tan'yū. The Kasuga neighborhood of Bunkyō takes its name from her. Another grave is in Odawara, Kanagawa Prefecture.
Lady Kasuga has been the subject of various films and television series, and has been a character in many more. Among the most prominent are these:
- Jotei Kasuga no Tsubone (1990, directed by Sadao Nakajima)
- Ōoku (2004) portrayed by Yuki Matsushita
- Kasuga no Tsubone (1989 NHK Taiga drama) portrayed by Reiko Ōhara
- Basilisk: The Kouga Ninja Scrolls (2005 anime and manga) voiced by Kimiko Saitō.
- Murdock, James. (1996) A History of Japan, p. 3.
- Jotei: Kasuga no tsubone at IMDB