Death Note story begins when Light Yagami (Raito Yagami) found a book that was owned by a Shinigami (death god) named Ryuk (Ryuku). Inside Ryuk's Death Note, there are ways to use the Death Note, written by himself. Death Note is then used to realize the ideals that is to create a clean new world of crime, with himself as god.
L is the world's top-rated detective and tasked with tracking down and arresting Kira. He often takes drastic strategies to confuse and force the hand of his opponents, and his disheveled appearance disguises his brilliance. He enjoys sugar, and in nearly every scene including him, he is found eating cake or confectionery and drinking highly sweetened coffee. L often misleads people with his behavior as well as his appearance. He sits in an unusual position, and he always wears the same articles of clothing.
The main character in Death Note, Light is an extremely intelligent, yet bored 17-year old student who is not satisfied with the current justice system. When he finds the Death Note intentionally dropped in the human world by the shinigami Ryuk, he decides to use it to kill criminals. He earns the title Kira, the Japanese pronounciation of the English word killer. His ultimate goal is to cleanse the world of evil and create a world without criminals. He intends to reign over this new world as its "god" and goes mad with power.
A girl with an immense crush on Kira, Misa is a popular Japanese idol. She is immature and tends to refer to herself in the third person in an attempt to be cute. She is completely devoted to Light, saying that she loved him at first sight, although the feeling is hardly mutual- since Light merely views her as a rather annoying asset and uses her. In the manga version, she kills herself after Light's death, which is implied in the anime's finale. What happens to her after the film version is uncertain- the only remaining characters whose fates are revealed are L and the Yagami family.
A calm and stoic character that appears in the second half of the series. He subtly represents an albino-like figure with his white hair, and plain white clothes. In the anime and manga versions, Near is a primary candidate to become L's successor and calls himself N during the course of his investigations. He shares a number of similarities with L. Much like how L plays with things such as sugar cubes and forks, Near is frequently shown playing with toys or his hair, and he is constantly shown sitting in an unusual manner. Also, like L, Near likes to stack objects such as dice, while L likes to stack sugar cubes.
Mello, a character present in the anime and manga versions, was an orphan who grew up with Near and Matt in Wammy's House, Watari's shelter for "gifted" children. Like Near and Matt, Mello was one of the candidates to become L's successor. Similar to L's fondness for sweets, he is often seen eating bars of chocolate. Although Mello is quite intelligent, he often lets his emotions get the better of him. His goal in life is to surpass L and Near. His real name is Mihael Keehl. Mello does not appear in the films. Mello was also killed by minor charactor Takada Kiyomi.