Height: 5'8"
Weight: 110 lbs.
Likes: Sweets
Dislikes: Wearing Socks
(Source: Death Note vol. 13 Profiles)
L, who also uses the aliases Hideki Ryuga, Ryuzaki, Eraldo Coil and Deneuve, the latter two for which he has developed reputations as the second- and third-best detectives in the world, is quite secretive and only communicates with the world through his assistant Watari. He never shows his face to the world, instead representing himself with a capital L in Cloister Black font. After meeting the Kira investigation team, he requests that the task force refer to him as Ryuzaki for discretion. The Kira investigation team never learns his true name. Ohba said that L is the smartest character in the manga because "the plot requires it." Ohba also said that he personally views L as "slightly evil"; for instance, in chapter 109, Near discloses the fact that L claimed to pursue cases out of personal interest with no great sense of justice.
When asked about L's nationality, Ohba responded saying "I think of him as a quarter Japanese, a quarter English, a quarter Russian and... maybe a quarter French or Italian? Something like that."
Tom S. Peperium of IGN described L's voice in the English anime version as "low monotone, while inspired by the original Japanese actor, sounds like a man deep in thought, a master detective on the hunt."
Ohba said that his favorite human character in the series was L as Ohba believed that L was the "strongest" character in the series "besides Light." Obata chose L as his favorite due to "appearance, personality, everything." Obata said that he could never have created L and that he enjoyed drawing L. Obata added that because of this, L is not "real" to him and therefore he likes that aspect of L. In response to the question "Who was the most fun to draw?" both Ohba and Obata answered "L."
L's disheveled and languid appearance masks his great powers of deduction and insight. He tends to second-guess everything he is presented with, and is extremely meticulous and analytical. He has several quirks such as preferring to crouch rather than sit, eating only sweet foods like desserts and fruits, and holding items very delicately. L stayed in England for five years, and during that time he was the champion in tennis for the England Junior Cup. L also secretly assumes the identities of the world's second and third best detectives, (Eraldo Coil and Deneuve respectively).
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. He also says that if he sits normally, his reasoning ability would drop 40%.
Whenever L gives percentages to indicate how much he suspects a person of committing a crime, such as "five percent," in reality he means over 90 percent. Although L gives Light a low percentage indicating how much he suspects Light, in reality L is "pretty certain" that Light is Kira. Ohba said about L, "The truth is, he's a liar."