Death Note:

Light Yagami, an extremely intelligent young man who resents the crime and corruption in the world, 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 human's name is written within it, that person shall die. 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 International Police Organization and a mysterious detective known only as "L".