Let's Sleep!: The Chang Family Series Board Book

At bedtime, Dad reads Min and Hwa a story about the Moon and the Sun. They wish upon a shooting star, and the stars come to their window! Min becomes the bright Sun, but Hwa is afraid of the dark. After learning about a firefly, she becomes the gentle Moon who shines at night. Just like the Korean folktale the author learned as a child, the Moon and Sun take turns lighting up the world.