Born in Seoul, Lee Seog-gu graduated from Kookmin University with a major in visual communication design. He has written the picture books Pit-a-Pat, Hide and Seek, Baby Breeze, and The Whole World Is White. He has illustrated the books A Puppy Goes to the Chicken Farm, The Best Baker Wears a Skirt, and Rock, Paper, Scissor, and Cheer Up!