In Tokyo, a disaffected high school student named Light Yagami finds the "Death Note", a mysterious black notebook that can kill anyone as long as the user knows both the target's name and face. Initially terrified of its god-like power, Light considers the possibilities of the Death Note's abilities and kills high-profile Japanese criminals, then targets international criminals. Five days after discovering the notebook, Light is visited by Ryuk, a "shinigami" and the Death Note's previous owner. Ryuk, invisible to anyone who has not touched the notebook, reveals that he dropped the notebook into the human world out of boredom and is amused by Light's actions.As criminals around the world die from inexplicable accidents and heart attacks, the global media suggest that a single mastermind is responsible for the mysterious murders and name them "Kira" (キラ, the Japanese transliteration of the word "killer"). Hoping to apprehend Kira, Interpol requests the assistance of an enigmatic consulting detective, known as L, to assist their investigation. Deducing that Kira is based in Japan, L tricks Light into revealing that he is in the Kanto region of Japan by manipulating him to kill a decoy.

Furious, Light vows to kill L, whom he views as obstructing his plans. L deduces that Kira has inside knowledge of the Japanese police investigation, being led by Light's father, Soichiro Yagami. Under the suspicion that "Kira" could have family ties with members of the "Kira" investigation, L assigns a team of FBI agents to monitor the families of those connected with the investigation and L learns enough to designate Light as the prime suspect. Around this time, Light graduates from high school to college. L recruits Light into the Kira Task Force, with each trying to get the other to reveal crucial information.

Actress-model Misa Amane, having obtained a second Death Note from a shinigami named Rem, makes a deal with Rem for shinigami eyes, which reveal the names of anyone whose face she sees, at the cost of half her lifespan. Seeking to have Light become her boyfriend, Misa uncovers Light's identity as the original Kira, but Light has another motive: he intends to use Misa's shinigami eyes to discern L's true name. L deduces that Misa is likely the second Kira and detains her. Rem threatens to kill Light if he does not find a way to save Misa. Light arranges a scheme in which he and Misa temporarily lose their memories of the Death Note, and has Rem pass the Death Note to a less morally driven individual, Kyosuke Higuchi of the Yotsuba Group. With memories of the Death Note erased, Light joins the investigation and, together with L, deduce Higuchi's identity and arrest him. Light regains his memories and uses the Death Note to kill Higuchi, regaining possession of the book. After restoring Misa's memories, Light instructs her to begin killing as Kira, causing L to cast suspicion on Misa. With Light insinuating the investigation would lead to Misa's capture and execution, Rem realizes Light's plan all along was to have her sacrifice herself to kill L, as a shinigami may not kill others to prevent a human's death. After Rem kills L, she disintegrates and Light obtains her Death Note. The task force does not announce L's death and agrees to have Light operate as the new L. With Light working as both L and Kira, the investigation stalls but crime rates continue to drop as he no longer has a threat of capture.

Four years later, cults that worship Kira have risen. Two young men, raised as potential successors to L, are revealed: Near and Mello. Mello joins the mafia whilst Near joins forces with the US government. Mello kidnaps Director Takimura, who Light then kills, so Mello, kidnaps Light's sister and exchanges her for the Death Note, using it to kill almost all of Near's team. A Shinigami named Sidoh goes to Earth to reclaim his notebook and ends up meeting and helping Mello. Light uses the notebook to find Mello's hideout, but Soichiro is killed in the mission. Mello and Near exchange information and Mello kidnaps Mogi and gives him to Near. Kira supporters attack Near's group, but they escape. Aizawa becomes suspicious in Light and meets with Near. As suspicion falls again on Misa, Light passes Misa's Death Note to a fervent supporter of Kira, Teru Mikami. He also appoints newscaster Kiyomi Takada as Kira's public spokesperson. Near has Mikami followed whilst Aizawa's suspicions are confirmed. Realizing that Takada is connected to Kira, Mello kidnaps her. Takada kills Mello but is killed by Light. Near arranges a meeting between Light and the current Kira Task Force members. Light tries to have Mikami kill Near as well as all the task force members, but Mikami's Death Note fails to work, having been replaced with a decoy. Perusing the names Mikami had written down, only Light's is missing, which proves Light is Kira. Light is grievously wounded in a scuffle and begs Ryuk to write the names of everyone present. Ryuk instead writes down Light's name in his Death Note, as he had promised to do the day they met, and Light dies.

One year later, the world has returned to normal and the Kira Taskforce Members are conflicted over whether they made the right decision. Meanwhile, cults worshipping Kira have risen, led by a woman resembling Misa. Three years later, Near, now functioning as the new L, receives word that a new Kira has appeared. Hearing that the new Kira is randomly killing people, Near concludes that the new Kira is an attention-seeker and denounces the new Kira as "boring" and not worth catching. A shinigami named Midora approaches Ryuk and gives him an apple from the human realm, in a bet to see if a random human could become the new Kira, but Midora loses the bet when the human writes his own name in the Death Note after hearing Near's announcement. Ryuk tells Midora that no human would ever surpass Light as the new Kira.

1 新生 Rebirth (Awakening of God)

Brilliant but bored high school student Light Yagami discovers a Shinigami's notebook and plans to use it to create a better world.

2 対決 Confrontation

The series of mysterious deaths catches the attention of world-renowned detective L, who confronts the killer on live television.

3 取引 Dealings

As the Task Force and L's investigation deepens, Ryuk tells Light that someone is shadowing them. Light needs the man's name, and Ryuk makes an offer.

4 追跡 Pursuit

While formulating a plan to get the name of the man following him, Light tests the limits of the Death Note.

5 駆引 Tactics

Soichiro confronts L about the FBI agents investigating the police, and Light makes a move against the FBI.

6 綻び Unraveling

Light runs into a woman at the police department who has information for L that could lead to Light's capture.

7 曇天 Overcast

The woman who could lead to his capture gives Light a false name. Light needs to act fast before the Task Force hears from her.

8 目線 Glare

The Task Force focuses on the people Raye Penber was tailing. Under L's intense surveillance, Light must figure out a way to clear his name.

9 接触 Encounter

L makes a direct move against his top suspect when Light enters To-Oh University.

10 疑惑 Doubt

L challenges Light to a tennis match and tests his deductive abilities; an urgent call has them rushing to the hospital.

11 突入 Assault

Video tapes reportedly from Kira air on Sakura TV, although L suspects that this is the work of another Kira.

12 恋心 Love

Light is invited into the Task Force to help respond to the second Kira, and Rem tells Misa how she came by her Death Note.

13 告白 Confession

Misa sends another message to Sakura TV to arrange a meeting with Kira. When the police offer a deal, she instead goes to introduce herself to Kira.

14 友達 Friend

Misa decides to help Kira, and Light wonders if she will make trouble for him in the future. To make Misa happy, Rem agrees to kill L.

15 賭け Wager

16 決断 Decision

17 執行 Execution

18 仲間 Ally

19 松田 Matsuda

20 姑息 Makeshift

21 活躍 Performance

22 誘導 Guidance

23 狂騒 Frenzy

24 復活 Revival

25 沈黙 Silence

26 再生 Renewal

27 誘拐 Abduction

28 焦燥 Impatience

29 父親 Father

30 正義 Justice May

31 移譲 Transfer May

32 選択 Selection May

33 嘲笑 Scorn May

34 虎視 Vigilance

35 殺意 Malice

36 1.28 1.28

37 新世界 New World