When Kazane Kajiya voluntarily sterilised herself in the United States aged 27, she essentially "flipped the middle finger" at Japan's patriarchal society that had long pushed her towards motherhood.

In the rapidly ageing country desperate to boost its falling birth rates, women seeking to make themselves infertile were assumed "not even to exist", Kajiya, who has never wanted children, told AFP.

Originally published on doc.afp.com, part of the BLOX Digital Content Exchange.