Japan's first lady Akie Abe joined the annual gay parade in Tokyo Sunday to show her support for sexual minorities.

The 51-year-old wife of conservative Prime Minister Shinzo Abe donned a white suit to stand on a float with a drag queen, as some 3,000 participants marched through the trendy Shibuya business and shopping district.

Akie Abe, known for her liberal inclinations, wrote on her Facebook page later that she has been involved in the issue since joining a commission set up by UNAIDS and the Lancet medical journal last year.

"I want to help build a society where anyone can conduct happy, enriched lives without facing discrimination," she wrote.

"I had the pleasure of spending fun time filled with smiles. Thank you," she wrote.

Her husband spent the day in northern Japan meeting residents of communities badly damaged by a deadly tsunami in March 2011.

Unlike traditional Japanese first ladies, Akie Abe has projected a cheerful confidence, freely speaking her mind and making remarks that often resonated well with the modern public.

She has voiced her opposition to nuclear power and scepticism about a trans-Pacific trade deal, and has passionately embraced Korean pop culture.

She has served as a counterbalance to her husband, known for his hawkish politics and support for nuclear power. Relations with South Korea and China have been frosty during his time in office.