Death Note is full of symbolism, from the Christian and Roman overtones (Apples, Divine Rule and the Shinigami Realm) to literary masterpieces (MacBeth, Julius Caesar and Sherlock Holmes), Death Note has become one of the few anime to have extremely deep roots in both American and Japanese cultures.
The most obvious symbols used in the series are Apples and the conflicting ideals of Justice between L and Kira.
Apples are complex symbols, having a variety of meanings and incorporations within a variety of contexts. They can mean knowledge, wisdom, luxury, joy, and/or death. In Greek mythology, apples appear repeatedly: the goddess Hera received an apple as a gift of fertility upon her engagement to Zeus, King of all Gods. Apples, in regards to the Garden of Eden, were the first symbol of temptation and Original Sin (note that this was an oversight by Ohba, as the actual forbidden fruit was unidentified). In secular ideology, apples function as a symbol for totality, as in the “cosmos” or “universe”, due to their nearly perfect spherical shape.
In the bible, if someone ate the forbidden fruit, they would become smarter, their eyes opened, and brought into a new conscious. Originally, Ryuk didn’t care about the human world. But as he ate the apples, and the series progressed, he slowly developed feelings for humans, just like in the Bible, when Adam and Eve came into a new conscious by eating the apples.
Justice has many underlying meanings. To understand the concept completely, we must first examine the origin of law begun by Hammurabi of Babylon (1795 BCE) as well as the Bible (Old Testament: 450 BCE, New Testament: 45-140 CE). In addition, we must also analyze the various goddesses of Justice: Ma’At (Egypt), Themis (Greek), and Justitia (Roman).
The first written code of laws was written by Hammurabi of Babylon, whose name translates to “the kinsman that heals.” He is the first (known) historical creator of what we call Justice, or Law. His code of laws are still in practice by people all over the world to this very day, whether they know it or not. Without Hammurabi, laws and morality would probably not exist as they do today. That is how important his work was to the entire planet.
Fans often speculate on how L promotes the death penalty but not Kira, although this may be simply that Kira’s judgment is not as wise as proper trial.
L also mentions that Kira may have a “childish” concept of right and wrong.
Many other contributions have been made since then, including: Rome’s creation of the original justice system, the Confucian belief system and philosophy as well as America and it’s ideal-driven culture.
The entire storyline of Death Note is similar to Shakespeare’s Julius Caesar. Light Yagami can be compared to Marcus Brutus, Misa Amane to Cassius (often speculated that Cassius was gay), L to Julius Caesar and Mello & Near to Mark Antony & Octavius Caesar. Just as Caesar’s ghost appears to Brutus before the decisive battle, an image of L returns to Light after the time-skip during a pondering moment of Light on Mello and Near. (However, the motives are different. Brutus perceived Caesar as a threat and loved both him and Rome enough to slay.)
Just before Light has Rem kill L, L receives prophecies of his death in the forms of images and dreams (more than once). In the same way, Jesus prophesied (more than once) that He would be betrayed and killed. Also, Jesus washes the feet of His disciples, including Judasâ€”just before the latter betrayed Him. In the same way, L washes Light’s feet after their conversation in the rain on lying (although this scene was not in the original manga, only the anime).