Long long time ago, there was a commune on the top of a mountain. In this commune lived two boys and five girls, and they liked living in the mountain because there they lived the simple life. Then, a famine came, and they had to leave their commune to look for food.
While they were searched, each of them told a story story to keep themselves amused while their stomachs were grumbling. The weather worsened, and made their journey difficult. They came upon a river which was almost impossible to cross. They formed a human bridge so that the lightest of their number could cross the raging river. Now that one crossed, the rest worried about how they would be able to cross the river -- but the girl who finished crossing the river, started laughing instead of worrying.
She thought this is still part of their stories and she just stood there laughing and did not think of helping her friends and she just laughed and laughed until her stomach exploded. From her stomach burst forth her kidneys which became the kidney beans and nourished her friends so that they did not have to cross the river any longer.
Source: Philippine Myths [ hawaii.edu