Koshiba Fuka is a Japanese actress represented by Oscar Promotion. She was born in Sakai Ward, Sakai City, Osaka, Japan.

On October 30, 2011, she won the 15th All Japan Figure Skating Novice Championship. In November of the same year, she won the "Aeon x Oscar Promotion Her Girls Audition 2011" Grand Prix. She later participated in Oscar Promotion's annual photo session for the first time on December 8. In April 2012, she made her commercial debut with "Aeon Grand Generation". In July of the same year, she debuted as an actress in the drama "Iki mo Dekinai Natsu" as the younger sister of her senior from the same agency, Takei Emi.

In March 2014, she made her movie debut through her first film, "Kiki's Delivery Service". In October, she started broadcasting her program, "Koshiba Fuka's Colorful Morning". In February 2015, she won the rookie award through both the 57th Blue Ribbon Awards and the 24th Japanese Movie Critics Award for her role as Kiki in "Kiki's Delivery Service". In October, she began playing the heroine role for her first stage show.

In January 2016, she appeared in her first asadora with her role as the heroine's daughter in "Asa ga Kita". She graduated from high school later that same year, on March 12. On March 15, her 1st photobook was released. She also appeared on a live special program that celebrated the anniversary of the end of World War 2. In January 2019, she became the main MC of a variety show. That same month, she starred in her first drama with "Tokusatsu Gagaga". That same year, her second photobook was released.

In April 2020, she made her first appearance as a drama heroine through "Gourmet Detective Akechi Goro". Edit Biography