This and another painting appear on the front doors of almost every temple in Taiwan. Maybe China as well. The story (according to the book I found in our school library) goes that a squat dark man and a tall, ghostly white man were ostracized in their town for being different. They made their homes outside the gate and danced and played at night so that they wouldn't scare the people. One night, an evil spirit came to invade the town, but it was scared away by these two men who did not seem to be afraid of it. After this, the people of the village celebrated the guardians, painting them on the doors of temples to ward off evil spirits.