The series is about Light Yagami, a young man who resents the crime and corruption in the world. His life undergoes a drastic change when he discovers a mysterious notebook, known as the "Death Note", lying on the ground. The Death Note's instructions claim that if a person's name is written within it while picturing that person's face, that person shall die. Light is initially skeptical of the notebook's authenticity, but after experimenting with it, he realizes that the Death Note is real. After meeting with the previous owner of the Death Note, a shinigami named Ryuk, Light seeks to become "the God of the New World" by passing his judgement on those he deems to be evil or who get in his way.
Soon, the number of inexplicable deaths of reported criminals catches the attention of the National Police Agency and a mysterious detective known only as "L". L quickly learns that the serial killer, dubbed by the public as "Kira" (キラ, derived from the Japanese pronunciation of the word "killer"), is located in Japan. L also concludes that Kira can kill people without laying a finger on them. Light realizes that L will be his greatest nemesis, and a game of psychological cat and mouse between the two begins.
L: Change the WorLd (also known as Death Note: L, change the WorLd or Death Note III), directed by Hideo Nakata, is a spin-off film and a sequel to the Death Note film series. The series is based on the manga Death Note by Tsugumi Ohba and illustrated by Takeshi Obata, but follows an original storyline. The film was released in Japan on February 9, 2008, Hong Kong on February 7, 2008, Singapore on February 21, 2008, and the United Kingdom on December 29, 2008.
Two versions of the film were shown in the United States on April 29 and 30, 2009. The first version of the film shown was in Japanese with English subtitles and the second version shown was dubbed in English with the same voice actors from the English dubbed Death Note anime like the US release of its predecessors.
Sumber : http://en.wikipedia.org/wiki/Death_Note_(film)