Japan has an estimated 2.74 million people who are either lesbian, gay, bisexual or transgender, and in terms of targeting a niche market, they have a combined purchasing power of 6.64 trillion yen -- the equivalent of the nation's liquor consumption.

This is according to Tokyo-based marketer Pageanta Co., which sees many of the people in the so-called LGBT segment willing to spend vast sums on lifestyle-related items from fashion and art to travel.

"Their buying power is undeniable," said Yuko Hakoishi, founder and president of Pageanta, which operates a social networking site for its target clientele.