Yonkoma is the term used for the four-panel comics which debuted during the series and were then later released in Death Note: How To Read 13. They were originally included in Shonen Jump 2004 #4/5 as a Christmas bonus, then appeared later in Akamaru Jump.

In Death Note: How To Read 13, pgs. 216-224 cover all of the four-panel comics. Pages 216-217 show the yonkoma that were published in Akamaru Jump 2004 Spring. pages 218-219 show the yonkoma that were published in Akamaru Jump 2004 Summer. Pages 220-221 show the yonkoma that were published in Akamaru Jump 2005 Winter. Pages 222-223 show the yonkoma that were published in Akamaru Jump 2005 Spring. Page 224 has the Shonen Jump Gag Special 2005.

The characters are given an introduction in Death Note: How To Read 13 because they are slightly different from their counterparts in the series. Of course, the yonkoma are for comical reasons, so even their introductions are semi-humorous.

• Light: "The chosen brainiac with a knack for funny comments. His serious demeanor makes him the butt of jokes."

• L: "Holder of the world's greatest mind and the powerful ability to act like a fool. It's like he was born to be mocked."

• Misa: "Along with Sayu, one of the two heroines of our story. Check out her sexiness, which has received a power boost compared to the main series."

• Ryuk: "A weird guy with a passion for apples. He may be the character that's least different from his series version."