Koyuki Higashi, a Japanese model and television personality turned LGBT activist, and her partner of four years, Hiroko Matsuhara, are the first same-sex couple to be granted Shibuya ward's certificate recognizing a same sex union.

"I'm so happy," Higashi says. "When they gave us the certificate, I cried. Our friends cried."

Applicants must be at least 20 and fill out a notarised document promising to protect each other and live together with trust and love.

This kind of certificate is only available for residents in two of Tokyo's 23 wards and although it is officially administered, businesses, hospitals, landlords, and other entities are not legally bound to acknowledge it.

Japan, same-sex couples have difficulty finding housing, opening joint bank accounts, and can be barred from seeing their loved one in the hospital after an accident or illness.