When Duncan arrives at school one morning, he finds a stack of letters, one from each of his crayons, complaining about how he uses them.

Returning to her childhood home after nearly two decades and reeling from upheavals in her world, Noel Post inherits her father's bookstore and begins receiving letters from an anonymous source, each one containing thoughts and lessons about her life and her future, and as she begins to reacquaint herself with the bookstore and the people she left behind, Noel starts to unravel the reality of her painful childhood and the truth about her family.

Stumbling on the same mysterious love letter in turn, best friends Hedgehog, Bunny, and Squirrel are reminded of the joys of friendship following a silly mix-up about their secret admirer.

In a series of letters a student laments the absence of her teacher and daily routine, but she soon realizes there are benefits to mixing things up, and that perhaps having a substitue teacher is not so bad afterall.

Brother chronicles life with his frequently-annoying Sister, from the time she is born until she is ten and he leaves for college, through a series of letters and drawings.

When life on Earth becomes unfair, Sophia tells her mother through a series of letters that she is moving to the Moon.

A letter from someone who was once an exasperating second-grader reveals her experiences with a teacher who brought out the best in her.

When Arfy finds a homeless kitten, he writes letters to prospective owners, hoping to find the perfect home for his new friend.

In the aftermath of a fatal car accident, a private journal of love notes written by a husband to his wife passes into the keeping of a hospital patient, and from there through the hands of five other suffering people, touching each of them uniquely.