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 of representing himself with a capital L in Cloister Black font. After meeting the Kira investigation team, he requests that the task force refers to him as Ryuzaki for discretion. The Kira investigation team never learns his true name. 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. He stayed in England for five years, and during that time he was the champion in tennis for the England Junior Cup. 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%. (Source: Wikipedia, Death Note Profiles)

The series' protagonist. A young arms dealer and the daughter of Floyd Hekmatyar, a global shipping magnate . Belongs to HCLI's European and African Logistics Division. She is physically attractive, with long silver-white hair, pale alabaster skin, striking blue eyes and her trademark smile, which is present even under dire circumstances. She is extremely charismatic and bold, which earned her great success in her business as well as the fierce loyalty of her subordinates. While generally behaving in a bubbly and slightly childish manner, Koko is actually rather ruthless and has been called a 'monster' by various characters. R reveals that she has never shown her true emotions since he met her. Before the series, she showed far more emotion, begging her subordinates to save her when Hex attacked her. However, after Echo's death, she took his final words to heart and keeps smiling no matter the situation. Koko has shown deep attachment to her team in general, going so far as to use Jormungand to save them. She considers Jonah a little brother and is very affectionate towards him. Valmet has a crush on Koko, but whether Koko reciprocates the feelings is unknown. She has a soft spot for R and Echo. She hates her father, Floyd Hekmatyar, as he was the one who pushed his children in arms dealing.