He is voiced by Mamoru Miyano in Japanese, and by Brad Swaile in English. Interestingly, both voice actors also went on to voice Setsuna F. Seiei, the protagonist of the Gundam 00 universe of the Gundam franchise. In the live-action films, he is portrayed by Tatsuya Fujiwara.
Light Yagami appears in two of the three Death Note DS games, Kira Game and Successor to L. Light continues to be under the role of Kira in both games.
Light also appears as a Support Koma in the Jump Superstars and Jump Ultimate Stars video games. Light and Ryuk appear, writing the name of an enemy or enemies in the Death Note, with an apple falling from the sky afterward. After being hit with the apple, an opponent has only seconds to live before instantly K.O.ing a character.
Light Yagami is the first person who picked up the Death Note after Ryuk the Shinigami dropped the notebook into the human world. Originally believing it to be a practical joke, Light writes the name of a criminal he sees on television only to watch him die of a heart attack. Still skeptical as to the power of the Death Note, Light writes down the name of a man who attempts to sexually assault a woman, only to watch him get run over by a truck. Thoroughly convinced of the notebook's power, Light writes down the names of criminals he finds on the internet. Confronted by the notebook's original owner Ryuk, Light announces his plan to cleanse the world of evil and rule as God, or as the masses call him, Kira (a play on the English word "killer.")
Light is then challenged by the master detective L to reveal himself; out of anger of L's interference in his plan, Light accidently reveals his general location, causing L to approach the Kanto region of Japan. Unbeknownst to Light, his father Souichiro Yagami is hot on the case of Kira's identity and wherabouts. L teams up with the Japanese Task Force to find Kira.
Light continues to find anonymous ways to kill those who oppose him, while also gaining information from police records his father holds. L, suspicious of Light, uses surveillance cameras and audio bugs to monitor Light's actions. Light secretly writes names in the Death Note, clearing his name, but not L's suspicions. L then approaches Light at his new college and reveals his role as L, with the two genius students earning a rivalry between them. L then asks Light to join him and the rest of the Task Force in solving the Kira case. Light agrees, all the while monitoring L's actions.
Upon encountering the Second Kira, Misa Amane, Light is incarcerated. In an extremely elaborate plan, Light abandons the Death Note, losing all memory of his role as Kira. With his name fully c leared, he continues to help L and the Task Force in their investigations. After the Third Kira, Higuchi, is arrested, Light restores his lost memories when coming in contact with the Death Note and kills Higuchi. Light manipulates the Shinigami Rem into killing L with her Death Note. Light, in an act of victory, stares down to a dying L, grinning in a sinister manner.
With L dead, Light works with Misa to kill criminals again, until years later he is challenged by Near, the theoretical successor to L. Along with Mello, Near plans to help Light stop Kira, with Light now leading the investigation under L's alias. Light manipulates Misa and his old friend Kiyomi Takada into killing for him, ultimately killing Takada when her usefulness to him was lost. Also, Light enlists a fanatical man named Teru Mikami to kill criminals, following Mikami's chivalrous and judgemental nature. Near continues to suspect Light, and the two finally meet at an abandoned warehouse. Light tells Mikami to write down the names of everyone in the room using the Shinigami Eyes. In an odd twist, Light's plan is foiled by Near, who switches the notebook's to Light's shock. Light reveals his identity as Kira and attempts to write down Near's real name, only to be shot by Matsuda, one of Light's most trusting friends. Upon nearly being killed by Matsuda, Light struggles to escape his fate, only to finally be killed by Ryuk and his Death Note.
Light's final sight is a vision of L, his greatest rival.
Light is known to dress formally, much more formally than his rival, L. As a college student, he wears a formal school uniform. Light originally gains an egotistic and superior attitude, considering the world to be filthy and rotten with bad people. As an adult, Light's attitude borders on maniacal. He even considers killing his friends and family to keep his own motives together. He is not afraid to manipulate people for his own motives. Light later on becomes blind with power, and seems to follow his motives more to be a god instead of cleansing the world. Light's intelligence is staggering, as he consistently plans ahead to follow his plans while also earning the highest marks in his class before going off to college.