The Japanese first lady could be seen atop one of the carriages that participated in the parade.
She even uploaded photographs of the event on her Facebook page to the surprise of the participants and her followers on this popular social networking site.
"I want to help build a society where anyone can lead happy, contented lives without facing discrimination," she wrote on her page, in which she also thanked the more than 3,000 people who took part in the parade.
Her participation has found mention in some sections of the national media such as the local newspaper Asahi, while being hailed by other portals dedicated to the LGTB community such as LGTBQNation or the Gay Star News.
Abe "has projected a confident image and is not afraid to express her opinion freely", even if it "may be contrary to the policies of her husband", reported the Japan Daily News website.
Although the general tone of comments on Facebook and other internet forums was positive, there were also those who criticised her for "bringing her interests into the public domain" or for participating in the parade for "electioneering" purposes.
The 51-year-old spouse of the conservative leader is known for her liberal opinions as well as for her activism in different social causes such as AIDS prevention through a commission established by the UNAIDS organisation and the medical publication The Lancet.
Japanese law does not recognise marriage between homosexuals and also does not extend any kind of social protection to same-sex couples.
A Japanese court, however, opened the possibility of transsexuals adopting children in a ruling passed at the beginning of this month.
According to a recent survey done by the Kyodo agency, 52 percent of Japanese are not in favour of legalisation of gay marriages, while 62 percent confessed to "not being comfortable" with homosexuality.