For musician Peter Buffett and his wife Jennifer, philanthropy started in 1997 with a gift of $100,000 from Peter’s father, Warren Buffett, for them to give to an organization of their choice. As it turned out, this was a prelude of sorts: successive gifts from Dad of $10 million in 1999 and $1 billion in 2006 launched the young Buffetts into philanthropy in a profound and serious way.

They quickly felt that with $1 billion came not just opportunity, but also a responsibility to use those dollars wisely. So the Buffetts began to literally travel the world in search of a mission, eventually concluding that the world’s most undervalued asset is a girl. In response, they founded the NoVo Foundation to right the imbalance of power for women and girls. “We talk about reaching the last girl, the most exploited, forgotten-about, and invisible girl,” says Jennifer Buffett.

With NoVo, the Buffetts have chosen to pursue some of the world’s grittiest and most ubiquitous problems, like ending violence against women and girls everywhere. Committed to strengthening the nonprofits they work with, the Buffetts know that success will not come at the end of a project, but through long-term systematic change.

In 2008, the Buffetts received the Clinton Global Citizen Award for their efforts. But when listening to them speak, it becomes clear that their real reward comes in the form of the “heart-mending” hope they see in the girls they help.