Masaaki Shirami

Masaaki Shirami (白身 正亜希, Shirami Masaaki) is a criminal killed by Light Yagami as a part of an experiment to test the Death Note.

Plot
Shirami is a serial arsonist, committing a total of five cases of arson in norhter Tokyo, burning property completely to the ground and killing thirteen people. On November 5, 2003 (2006 in anime) he is arrested while attempting to commit a sixth arson.

In order to test the limits of the Death Note, Light Yagami writes Shirami's name. In his prison cell, listed as Prison #21, he cuts his finger and draws a five-pointed star inside of a circle on his cell wall. After doing so, Shirami dies from a heart attack.

Trivia

 * What Shirami drew was a pentagram, a symbol of the religion of Wicca. However, despite it's relation to the Wiccan religion, these pentagrams are often mistakenly associated with Satanism, which is possibly why Light chose to have Shirami draw this.