The Barbican site describes the story:
Issues of stardom – and fandom – are at the heart of this sweeping Japanese animation by Satoshi Kon (Paprika, Perfect Blue). Actress Chiyoko Fujiwara, an icon of 1950s cinema but now retired and living in seclusion, is visited one afternoon by a devoted fan wanting to make a documentary about her career. As they – and we, the audience – plunge back into her past, we hop between events in her real and her on-screen life in roles in a variety of genres and time-periods. Conceived as a homage to the samurai epics, domestic dramas, space odysseys and monster movies of post-WW2 Japanese cinema, the film sets up further resonances in the character of Chiyoko herself who recalls both Hideko Takamine, an icon of hope for post-war Japanese filmgoers, and Setsuko Hara, one of Yazujiro Ozu's favourite actresses, who disappeared from the public eye at the height of her stardom.