There has been controversy regarding Brian's grasp of the characters' names and physical appearances. Throughout the beginning of the series, when the character of Kiki is first introduced, her last name is Rosen. However, her name is later switched to Kiki Thorpe. Additionally, the eye color of certain characters, including Josh Hollis, Thomas Pearson, and Ivy Slade, changes throughout the series. A critic stated in a review for "Amazon.com" that the appearances of many of the secondary characters, with the exception of a few, changes "with each new installment."