“If we catch Kira, he
is evil, if he wins and rules the world, then he is justice.”
-Light Yagami
(“Justice”)
Yagami Light is a hardworking,
talented, and a natural genius. His only faults are his deep sociopathic
interior, his cynical outlook on life, his overconfidence in himself and his
belief that he is never wrong. L describes both himself and Light as “childish
and hating to lose”.
 Ohba said that Light was “a young
man who could understand the pain of others” when he first encountered the
Death Note. Ohba said that if Ryuk never developed an interest in the human
world,
Ohba said that Light was “a young
man who could understand the pain of others” when he first encountered the
Death Note. Ohba said that if Ryuk never developed an interest in the human
world, 
Light would have become “one of
the greatest police leaders in the world” who, with L, worked against
criminals. Indeed, wouldn’t it have been great to see Light and L work together
(like they did when Light lost his memories of the
Death Note), instead of “hunting” each-other? Though the competition and mind games between them are
very interesting and keep you on the edge of your seat.
Ohba described Light’s life
“ruined” once he obtained the Death Note, and that Light became a
victim of the Death Note “in many
ways”.
The Death Note represents power
and humans become easily corrupted by it. Especially a human
with a strong sense of justice
and high morals, like Light. Though hesitant in the beginning, Light uses
the Death Note with more
confidence every time and gradually loses his humanity becoming this cold,
ruthless, and malevolent being
that people call Kira. He becomes completely devoid of love,
compassion and mercy. He views
himself as the only rightful savior of mankind and he’s convinced that all his
actions are justified, no matter how inhuman they might be. He is shown to even
be willing to sacrifice his own family, if pushed to that point. He is so
convinced that what he is doing is right that he never falters in his beliefs
of creating a utopia (that is actually a dystopia), even when he crosses the
thin line between punishing criminals and killing innocent people for the sake
of “justice”. Light is a complex, layered character that, unlike L, doesn’t get
emotionally involved with anything or anyone, which makes him seem like the
winner.
 Trivia:
 -Kenichi Matsuyama (L) and Tatsuya Fujiwara (Light) became
“so immersed” in their character portrayals, that they did not talk to one
another while on the set; only when filming ceased did they converse and “went
out for a drink or two”;
-Tatsuya Fujiwara said that he felt difficulty portraying
Light because he has no signature mannerisms (like L) and therefore has his
feelings displayed by his face;
    
-Fujiwara explained that he wanted Light to cry in a
particular scene even though the director told him that “Light doesn’t cry”,
since the actor believed that the scene would feel “more honest”;
-The actor said that he “could understand” Light’s
intentions to create a new world even though “murder is a horrible thing”;
-According to Ohba, Light sees Misa Amane, who he uses as an
accomplice, as a “bad person” who killed people, so he acts emotionally cold
towards her and manipulates her. Despite this, he keeps her alive even after
her memories of being Kira have been removed for the second (and final) time;
-The name Yagami literally means “night god”.
  
“Risking your life
and doing something that could rob you of your life are exact opposites.”
-L (“Hard Run”)
L decides to act based on the saying: “Keep your friends
close and your enemies closer”. In my opinion he gets involved more than Light
does and genuinely expresses his feelings to him: “Light-kun is my first
friend”. This shows his humanity. All the eccentric quirks he has acquired are
said to be due to the heavy strain of upholding the name of L (according to the
novel L: Change the World).
Writer Tsugumi Ohba said that L is the smartest character
“because the plot requires it”. He added that he personally views L as
“slightly evil”.L is quite secretive and cautious; he has great deductive
powers, though his appearance masks his abilities. Meticulous and analytical, L
is good at deceiving his opponents and is willing to take drastic measures to
solve a case. Some of his tactics are quite bold. Though he doesn’t show it in
an evident manner L does get involved in every case and is well aware of the
implications. 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 he is often seen sitting and inactive, L retains a
high athletic ability. In chapter 38 of the manga, L suggests that even though
he eats only sweet food, 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 by 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. 
Ohba said that his favorite human character in the series
was L because Ohba believed that the detective was the “strongest” character in
the series “besides Light”. Obata also chose L as his favorite due to
“appearance, personality, everything”. In response to the question “Who was the
most fun (character) to draw?” both Ohba and Obata answered “L”; 
Kenichi Matsuyama, the actor who portrays L in the movies,
described L and Light as having “such unique characters that they’re impossible
to understand” and that “the inside of L’s head remains a mystery” to him. Matsuyama said that L and
Light are “extremely” alike in that they have “very strong sense of justice”.
    
Trivia:
-Matsuyama
admits having experienced some difficulty in trying to portray L (especially in
emulating L’s postures). He decided to interpret him as an individual who does
not “quite understand other people on an emotional level”;
-Kira, L, Mello, Near are all in alphabetical order; Ohba
considered at first the initials “I” and “J”, but decided that they didn’t
“feel as good” as L. He mentions having given L the alias “Ryuzaki” because L
is pronounced like R in Japanese;
-L can tie two cherry stems in a knot with his mouth, as
seen in episode 18;
-The novel states that L helped in the prevention of World
War III when he was only eight years old;
-In the novel, L takes a few capoeira lessons from Suruga.
This is most likely a homage to the on-going fan speculation of L’s capoeira
like fighting style in the Death Note manga and anime;
-In the novel, L completely loses (for the first time) his composure
and calm attitude;
-In the novel it is described that L did consider Light to
be his friend, going as far as holding on to Light’s broken watch as a memento
and saying: “Light, I’ll see you on the other side. Let us explore the world of
nothingness together”;
-According to the timeline that is presented on each page of
the novel, it appears L was to have only 272 days left to live prior to writing
his name onto the page of the Death Note. Based on this bit of information it’s
obvious that L’s remaining natural lifespan at the end of the second movie
would only have amounted to less than a year.