The three young Singaporeans who started a flip-flop business more than five years ago have gained a certain amount of fame after walking into another line of work: corporate social responsibility consulting.

But what's really remarkable is that the two men, John Tay and Justine Lee, and one woman, Lim Jing Ying, are all just 24 years old.

Their clients include large multinationals like South Korean giant Samsung Electronics Co and Japan's Meiji Dairies Corp, as well as a long and impressive list of Singaporean companies and Chinese corporations like clothing maker Shanghai Huaxiang.