Luffy seems to have an unstoppable appetite, a characteristic that is common to the Japanese archetype of the (at times simple-minded) young male hero/adventurer with a heart of gold; perhaps the hunger more so in Luffy's case due to having an elastic stomach. Luffy is also another one of the several characters given the middle initial "D." Although Luffy is fairly lightheaded and a funny character, he has an unstoppable sense of determination, optimism, and commitment and will do anything to stand up for his friends and comrades. Along with that, he has great courage to back it up as well as unbelievable strength. Ever since consuming the devil fruit he was shown to be not worried about his inability to swim, much like his brother. Much of these traits are common among D's. His only display of true fear is towards his grandfather, to the point that he is intimidated at the mere mention of him. Luffy never kills any of his enemies, no matter how cold-hearted they are; instead, he frequently sends the villain flying, knocking them out or beating them to a point that they are almost near death, which results in some of the villains searching for revenge, such as Buggy the Clown and Alvida. Oda explains that it's not a question of morality so much as a matter of punishing the villains for their crimes - he feels that killing the villains lets them off too lightly, whereas he considers letting them live to see their dreams be ruined a far more fitting punishment. Luffy's dream is to find the One Piece and become Pirate King. He knows that to achieve his goal, he will have to defeat many strong opponents, including the World Government and his childhood hero Shanks.

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)