Part I

Part I is the first part of the anime and manga. This part primarily focuses on a mind battle between Kira, who is 17-year old Light Yagami, and L, an eccentric detective seeking to catch Kira. This part of the anime is often referred to "season 1" by fans.

Characters
The following is a list of characters featured in this part. Characters who are mentioned are italicized.
 * Light Yagami
 * L
 * Misa Amane
 * Ryuk
 * Rem
 * Gelus
 * King of Death
 * Soichiro Yagami
 * Naomi Misora
 * Kiyomi Takada
 * Watari
 * Touta Matsuda
 * Sayu Yagami
 * Sachiko Yagami
 * Kyosuke Higuchi
 * Raye Penber
 * Shuichi Aizawa
 * Lind L. Tailor
 * Yuri
 * Calikarcha
 * Gook
 * Deridovely
 * Zellogi
 * Wedy
 * Aiber
 * Hirokazu Ukita
 * Hideki Ryuga
 * Reiji Namikawa
 * Hideki Ide
 * Hitoshi Demegawa
 * Misa Amane's stalker
 * Arayoshi Hatori
 * Kiichiro Osoreda
 * Yumi Aizawa
 * Takuo Shibuimaru
 * Shingo Mido
 * Kurou Otoharada
 * Emi
 * Eiichi Takahashi
 * Eriko Aizawa
 * Koreyoshi Kitamura
 * Yamamoto
 * Yoshio Anderson
 * Masahiko Kida
 * Masaaki Shirami
 * Takeshi Ooi
 * Suguru Shimura
 * Ryo
 * Shiho
 * Ginzo Kaneboshi
 * Kyoko
 * Yukito Shiraba
 * Sudou
 * Nori
 * English teacher
 * Film director
 * Tasayoshi Yoda
 * Yasunaga
 * Sasaki
 * Yonegoro Nusumi
 * Unnamed woman
 * Yoshi
 * Light Yagami's friend
 * Misa Amane's friend
 * Matsushiro Nakaokaji
 * Imai
 * Ken Yadanaka

Episodes
The following is a list of episodes featuring this part.
 * Rebirth
 * Confrontation
 * Dealings
 * Pursuit
 * Tactics
 * Unraveling
 * Overcast
 * Glare
 * Encounter
 * Doubt
 * Assault
 * Love
 * Confessions
 * Friend
 * Wager
 * Decision
 * Execution
 * Ally
 * Matsuda
 * Makeshift
 * Performance
 * Guidance
 * Frenzy
 * Revival
 * Silence

Chapters
The following is a list of chapters/volumes featuring this part.

Volume 1

 * Boredom (退屈, Taikutsu)
 * L
 * Family (家族, Kazoku)
 * Current (電流, Denryū)
 * Eyeballs (眼球, Gankyū)
 * Manipulation (操作, Sōsa)
 * Target (標的 Hyōteki)

Volume 2

 * Woman (女, Onna)
 * Slots (穴, Ana)
 * Confluence (合流, Gōryū)
 * One (一, Hitotsu)
 * God (神, Kami)
 * Countdown (秒読, Byōyomi)
 * Temptation (誘惑, Yūwaku)
 * Phone Call (電話, Denwa)
 * Handstand (逆立, Sakadachi)

Volume 3

 * Trash (芥, Gomi)
 * Gaze (視線, Shisen)
 * Humiliation (屈辱, Kutsujoku)
 * First Move (先手, Sente)
 * Duplicity (裏腹, Urahara)
 * Misfortune (不幸, Fukō)
 * Hard Run (激走, Gekisō)
 * Shield (盾, Tate)
 * Fool (馬鹿, Baka)

Volume 4

 * Reversal (転倒, Tentō)
 * Love (恋心, Koigokoro)
 * Judgement (判定, Hantei)
 * Weapon (武器, Buki)
 * Bomb (爆弾, Bakudan)
 * Easy (簡単, Kantan)
 * Gamble (賭, Kake)
 * Removal (移動, Idō)
 * Imprisonment (投身, Tōshin)

Volume 5

 * Whiteout (白紙, Hakushi)
 * Father and Son (親子, Oyako)
 * Eight (八人, Hachinin)
 * Strike (打撃, Dageki)
 * Separation (離別, Ribetsu)
 * Allies (仲間, Nakama)
 * Matsuda (松田)
 * Heaven (天国, Tengoku)
 * Black (黒, Kuro)

Volume 6

 * Successor (後継, Atotsugi)
 * Crazy (無茶, Mucha)
 * Ill-Suited (不向, Fumuki)
 * Impertinence (先走, Sakibashiri)
 * Give-and-Take (交換, Kōkan)
 * Potted Plant (植木, Ueki)
 * Yotsuba (四葉)
 * Misunderstanding (誤認, Gonin)
 * Split-Second (寸止, Sundome)

Volume 7

 * Scream (悲鳴, Himei)
 * Inside (中, Naka)
 * Creation (創造, Sōzō)
 * Embrace (抱擁, Hōyō)
 * Two Choices (二択, Nitaku)
 * Feelings Within (胸中, Kyōchū)
 * Zero (零, Zero)