[2] In June 1946, Toho had sponsored a search for "new faces", choosing Kuga as one of 48 new actresses and actors from 4,000 applicants.

[3] In 1947, she made her debut as one of the lead actresses in the omnibus movie Four Love Stories (四つの恋の物語, Yottsu no Koi no Monogatari).

[3] In the 1950s, she started working independently and starred in many productions of the Shochiku studios under the direction of Keisuke Kinoshita.

Other important directors include Kenji Mizoguchi (The Woman in the Rumor), Yasujirō Ozu (Equinox Flower), and Tadashi Imai (An Inlet of Muddy Water).

In 1954, she co-founded the film production company Ninjin Club (Bungei purodakushon ninjin kurabu) with actresses Keiko Kishi and Ineko Arima to enable better working conditions for actors within the studio system.