Plan International works in 48 developing countries across Asia, Africa and the Americas. Its mission is to help improve gender equality. It has just launched a global campaign called "Because I am a Girl", which includes a photo competition.
Nine women who are leaders and role models in their fields have become ambassadors for the cause, sharing their views and experiences with the public.
Christine Liao, better known by her stage name as Mao Mei, is one of them. She is an arts educator who founded the Christine Liao School of Ballet and helped set up the Hong Kong Ballet Company.
Liao was a famous movie-star ballerina in Putonghua movies between 1956 and 1963. She was born in Shanghai, but her family moved to Hong Kong when she was a teenager. "My parents let me explore my interests and allowed me to see the world," she recalls.
She studied dance in Britain and opened her first ballet studio in Hong Kong in 1964. Her ballet school has become one of the largest in the world. It has 30 some studios and has trained thousands of students, some of whom have become world-class dancers.
In 1987, Liao was appointed a Justice of Peace by the government in recognition for her contributions to arts education.
"All human beings are the same, whether male or female," she says. "If girls in the world are given education and opportunities, they can contribute a great deal to their community and double the strength of their country."
Statistics show she is right. Plan International cites studies that show that a significant increase in the female working population of India was instrumental in boosting the country's GDP. "Women can influence the world if we have dignity and self-respect and believe in what we do," Liao says.
Connie Wong Oi-yan is another ambassador for Plan. She's a pianist with an inspiring life story. Wong, who was named a Top Ten Outstanding Young Person last year, was born with only three normal fingers. She spent much of her childhood in pain, enduring one corrective operation after another. In hospital she passed the time by watching cartoons and got hooked on the theme songs.
"I wanted to play the songs," she says. So she asked her parents for piano lessons. "At first, my parents doubted I could do it, but they let me try because they love me."
Trying to play demanding classical compositions with only three fingers was a challenge, but Wong persisted. She eventually graduated from Chinese University in piano performance and went on to earn a doctorate in ethnomusicology from UCLA.
"When I was small, I used to think how nice it would be to have normal fingers," Wong says. "But my limitation has given me an extraordinary life."
Wong now tutors children with physical disabilities in piano and is a motivational speaker. "Hong Kong has many opportunities for young women. I feel sad when I see some of them wasting their lives," she says.