L Lawliet

L is a very slim, pale, tall young man with messy neck-length black hair and black eyes. One of his most noticeable features is the shadow below each of his eyes, a result of him being an insomniac. L is always shown to be wearing a pair of blue jeans and a long-sleeved white shirt. He almost never wears shoes or socks, preferring to go barefoot, even while in public. This was shown when he visited Light Yagami's school and was seen barefoot while sitting on a bench, not bothering to wear his shoes until he got up to walk. L also tends to hunch over when walking.

L is quite secretive, and only communicates with the world through his assistant, Watari. He never shows his face to the world in person, instead representing himself with a capital letter L drawn in "Old English MT" or "Cloister Black" typeface.

L is very intelligent, though his disheveled and languid appearance masks his great powers of deduction and many question his abilities upon viewing him. L tends to second-guess everything he is presented with, and is extremely meticulous and analytical. He is good at deceiving his opponents, and is willing to take drastic measures to solve a case. Some of his tactics are quite bold, such as having death row inmate Lind L. Tailor pose as himself on live TV in order to draw out Kira, while others seem bizarre to those involved, such as handcuffing himself to suspected-Kira, Light Yagami. He is also shown to have a dry sense of humor, and he isn't above making sarcastic remarks to people. Although he tends to be polite, to some (such as Task Force member Shuichi Aizawa), L can seem condescending at times.

Using subterfuge, misinformation, disinformation, and an analytical knowledge of human nature to help lure a suspected murderer into a false sense of security and possibly make him carelessly over-confident, L sometimes gets what he wants through abnormal or possibly criminal channels. Whenever L gives percentages to indicate how much he suspects a person of committing a crime, such as "five percent," he may in fact be over ninety percent convinced of their culpability. Although L tells Light that he is among the least likely suspects with one of the lowest percentages of probability, in reality L is "pretty certain" that Light is Kira. As series writer Tsugumi Ohba said laughing, making light of L's tactics: "The truth is, he's a liar."

He also has several quirks, such as preferring to crouch rather than sit, eating only sweet foods (like desserts, candies and fruits) and holding items by using only a thumb and a finger. He also has an unusual way of sitting, with both of his feet on the chair. He claims that if he sits normally, his reasoning ability would drop 40%. Interestingly, in the manga, he is seen sitting on the floor in a pose similar to how one would meditate, while thinking deeply about the Kira case. He is often seen arranging objects and very intently stacking, or in other ways playing with, his staple food items. L is almost always encountered while performing actions that are considered inappropriate or rude in public. These actions/habits include biting fingernails, placing feet on furniture, slouching, chewing with an open mouth, talking with his mouth full, and calling out personal observations that may offend others.

With his status as the world's greatest detective, he, like Light, has a very sensitive pride, being afraid to be wrong in his deductions and theories, evident through his drastic measures (torturing Misa and confining Light during an unnecessarily lengthy amount of time), and lethargic behavior during the beginning of the Yotsuba arc.

Although he is often seen sitting and inactive, L retains a high athletic ability. L stayed in England for five years, and during that time he was the tennis champion in the England Junior Cup. He also has a knack for martial arts, which is demonstrated in his brief fight with Light. In chapter 38 of the manga, L suggests that even though he eats only sweet foods, he remains underweight because the brain uses the most calories of any organ in the body.

L is a yandere type, who can be extremely possessive and rough.