Kei Aran (安蘭 けい Aran Kei?), real name Touko Yasuda (安田 瞳子 Yasuda Touko?) (born October 9, 1970), is a Japanese actress and former top star otokoyaku (an actress who plays male roles) of the Japanese Takarazuka Revue's Star Troupe. She joined the revue in 1991 and became the top star in 2007, five years after her classmates Sumire Haruno (the former top star of Flower Troupe) and Hikaru Asami (former top star of Snow Troupe) became top stars. She resigned from the company in April 2009 and is currently pursuing an acting career outside of the Revue.
She is original from Konan, Shiga, Japan, and her nickname is Touko.
She is of Zainichi Korean descent and the first from such background to become the top star of the company. However, she is not the first non-Japanese actress to become a Takarazuka top star: Ran Ootori, who is of Chinese descent, was top star of Star Troupe from 1975 until 1979.
Aran graduated at the top of her class from the Takarazuka Music School in 1991. She was the last member of her class to become top star, and also the last to retire from the Revue when she did so in April 2009.
She was one of the promising young stars that were promoted by the company in 1999 along with Haruno and Asami. Before she was promoted to top star status, she was considered as one of top-stars-in-waiting along with former Cosmos Troupe top stars Kei Takashiro and Yūga Yamato, former top star of Moon Troupe Jun Sena, and former top star of Snow Troupe Natsuki Mizu.