Best friends Lydia and Julie record their witty observations about what makes certain fifth graders popular in a notebook they pass back and forth. Their plan is to figure out the key to popularity by the time they enter middle school. Their year is peppered with activities to get people to notice them—all based on what the most popular girls do. While taking up knitting doesn’t prove to be effective, joining a stick-fighting club and the lacrosse team opens opportunities for new friendships. A real strength of this laugh-out-loud book is the unexpectedly deep and distinctive characterizations of Lydia and Julie, and the wonderful secondary characters, including Julie’s gay dads (one of who is Asian American) and Lydia’s rebellious older sister, Melody, a goth girl. An eventual fallout between the two best friends offers an opportunity to discover how much they’ve grown, which includes being able to sincerely say “sorry.” Amy Ignatow’s light, funny novel, written in two distinctive narrative styles (and fonts) and featuring numerous illustrations (also in two distinctive styles) is a perceptive and poignant commentary on friendship. (Ages 8–11)