Exploitative contracts that force young female Japanese pop stars to forego relationships and sex are at the heart of director Koji Fukada's latest film, which has premiered in Cannes.

The 45-year-old director said he was inspired by a news report about a Japanese "idol," as the stars are known, who was sued by her management agency after breaking a "no dating" clause.

Fukada cast former idol Kyoko Saito in the lead role of his feature "Love on Trial," which tells the story of a young performer who undergoes a similar ordeal.