Light Yagami

This L doesn't know who I'm messing with. Real good, not evil...

Through the use of the Death Note, Light quickly begins to develop a cold and ruthless nature. As a utilitarian, he will use any means necessary to achieve his goals and ambitions. However, though his actions do put his family in harm’s way, he continues to show love and genuine concern for them. This is demonstrated when his sister Sayu is kidnapped and held for ransom. Light prevents Soichiro from taking drastic action in order to keep Sayu safe, in spite of knowingly increasing Mello's chances of obtaining the Death Note.

Additionally, the series shows that Light was not born remorseless. After relinquishing the notebook and losing his memories to temporarily avoid suspicion, Light demonstrates compassion, a reluctance to manipulate others, and an intense unwillingness to kill. Once his memories return, however, he reverts to his ruthless Kira persona and remains that way until his death.

Light grew up in Japan with his family, which consists of his father, Soichiro Yagami, who is a member of the Japanese Task Force (an investigation team opposing Kira), his mother, Sachiko Yagami, and his younger sister, Sayu Yagami.

At the start of the series, Light is a third-year high school student (12th Grade) at Daikoku Private Academy and also attends supplemental classes at Gamou Prep Academy in the beginning of the story. He later attends college at To-Oh University (東応大学, Tōō Daigaku).

In the year 2003 (2006 in the anime), Light Yagami discovers a mysterious notebook on the ground at his school. Written on the cover are the words "Death Note". The Death Note's instructions state that if a human's name is written within it, that person shall die. Light is initially skeptical of the notebook's authenticity, but after experimenting with it, Light realizes that the Death Note is real.