Former news anchor and model Renho Murata has become the first ever female leader of Japan's left-of-centre Democratic Party.

Her election comes with women woefully under-represented in Japan's parliament, making up just 10% of MPs in Japan's lower house of parliament, and 20% in its upper house.

Known simply as Renho, she said her priority is to establish the party as a serious contender to the Liberal Democratic Party, which alongside its junior coalition partner dominates parliament.

Her election is expected to give the party a much-needed boost after polling poorly in recent elections, with Renho casting herself as the voice of a younger generation.

The 48-year-old was born in Japan to a Japanese father and Taiwanese mother, with the revelation that she had not renounced her Taiwanese citizenship in her teens as she claimed pounced on by campaign opponents.

A former swimsuit model, Murata worked as a journalist and TV news anchor before entering politics.

She was elected to parliament in 2004, and has campaigned on parenting and foreign policy issues, criticising the government's relationship with China as "too polite" as well as its refusal to recognise Taiwan.

She has served as Minister for Administrative Reforms in 2010 and State Minister of Government Revitalisation in 2011, with gender equality, civil service reform and addressing Japan's declining birth rate among her responsibilities in the latter position.

She has twins with her husband Nobuyuki Murata, a writer and academic.