Death Note, Vol. 1: Boredom by Tsugumi Ohba

When Light Yagami finds a notebook giving him power over death, will he use it for good—or evil? Light Yagami is an ace student with great prospects--and he's bored out of his mind. But all that changes when he finds the Death Note, a notebook dropped by a rogue Shinigami death god. Any human whose name is written in the notebook dies, and now Light has vowed to use the power of the Death Note to rid the world of evil. But when criminals begin dropping dead, the authorities send the legendary detective L to track down the killer. With L hot on his heels, will Light lose sight of his noble goal...or his life? Light tests the boundaries of the Death Note's powers as L and the police begin to close in. Luckily Light's father is the head of the Japanese National Police Agency and leaves vital information about the case lying around the house. With access to his father's files, Light can keep one step ahead of the authorities. But who is the strange man following him, and how can Light guard against enemies whose names he doesn't know?