In this low-key account of imaginative play, nine classmates spend a day making up pleasant activities. Each time "someone" proposes a game, the rest happily cooperate. When they arrive at school, "Someone says, 'Let's leapfrog in.' And... spring-boink, spring-sproink we do." As the smiling children hop, frog shapes in neon-bright outlines are superimposed on their bodies. Later, during art class, "Someone says, 'Mei Lin can't stand still. Let's draw her dancing like a pony.' " A lively girl, drawn in gestural black ink strokes, prances and bows while her friends use bamboo brushes to paint curvy blue and purple horses. Schaefer and Morgan (who previously teamed up for The Squiggle and Snow Pumpkin) imply the classmates' Asian heritage with visual motifs such as ink stamps, and their fanciful creations include classical singers with white-painted faces and flowing kimonos. With chopsticks (or their hands), the kids play at being hungry tigers who "slip, sloop, slurp" a snack of noodles, and they pretend to build a multicolored pagoda from mundane wooden blocks. Morgan uses ribbony strokes of color to draw the nine individualized children, and an undecorated, tepid beige background leaches the heat out of her flushed pinks and intense blues. Despite the silliness of Schaefer's onomatopoeia and the mobile characters, this book's repetitive formula and mild pictures may suit restful readers better than a high-energy audience. Ages 3-7. (Sept.)