Silly Green Mask is about a very imaginative 3-year-old girl and her younger sister. At pre-school, the girl draws a silly face on green construction paper. Her teacher cuts it out, fashions it into a mask with eye holes, and attaches a string. The mask becomes a source of fun and theater for the girl, instantly turning her into an animated, make-believe character. One day, while wearing the mask, the girl becomes so wild that her little sister starts to cry. In an act of compassion, she makes a surprising decision.
Including in the book are the lyrics and music to four Japanese children's songs and a cut-out mask.
