Death Note 13: How to Read

Death Note 13: How to Read, also known as Death Note: How to Read 13, is an encyclopedia-style guide to the Death Note manga series, including character bios, storyline summaries, interviews with creators Tsugumi Ohba and Takeshi Obata, production notes and commentaries, and a bonus: the pilot chapter of the manga. It also includes Ryuk's Human Observation Journal.

Everything that is contained within this book is official, written by the original author and artist, and is considered canon across all spectrum of the Death Note universe. Included in it is a character card of L, which shows his real name.

The Japanese release also includes 5 finger-puppets as seen in the Death Note series in Near's possession:
 * Kira
 * L
 * Misa Amane
 * Near
 * Mello

Trivia

 * Viz's official English release incorrectly converts the characters' heights, apparently converting from centimeters to feet and then using the remaining decimal as inches instead of properly converting to inches. For instance, Light is 179 cm, which correctly converts to 5.87 ft, or 5' 10½," but Viz gives his height as 5' 8", apparently taking the eight inches from the .8 feet.
 * This is the final volume of the manga series, but the guidebook for the anime series, Death Note/A Animation Official Analysis Guide, is designed to go after it. The "/A" in the title is meant to resemble the number 14, following volume 13.