Light yagami

Light Yagami was a high school student who one day found a notebook called the "Death Note." At first, he didn't believe it and thought it was magic.

But then he tries it a few times. Ever since he found the notebook, a Shinigami, the "God of Death", has always been with him, named Ryuk (no human could see Ryuk or hear his voice except for demons and humans who touched the Death Notebook).

They became very close and Light found a goal: to kill all the criminals and those who stood in his way and transform the world into a world full of happiness. But he found an extremely dangerous enemy named L.

Of course, this was a nickname and no one knew L's real name, and even though Ryuk could see the names and dates of death of all humans, he didn't tell Light because it was against the rules of the Shinigami. One day, Ryuk brings Light news that a demon who looks very much like a human has come to the human world.

(In this world, demons have extremely high power, even higher than a Shinigami, and are extremely useful for Light's plan.)