Devil and Angel

In manga and anime, sometimes two small spirits, a devil and an angel, appear on a character's shoulder, over their head, and so on, to give them advice and tell them what to do.

Anime: Hayate no Gotoku! ハヤテのごとく！ (Episode 1)

• sasayaku
  囁く
  To whisper.

Typically, this is a comedic way to depict the conflict of good and evil inside the character when dealing with a situation.

• Examples
  
  • Other Internal Conflicts

Examples

The appearance of the devil and the angel tend to be based on the character. They may argue against each other, physically start fighting, or, in some cases, even agree with each other.

Often, the character will think about doing something evil, then the angel will appear and tell them to reconsider, then the devil appears and tells them to proceed, or vice-versa: the character stops himself, the devil appears, then the angel.

Character: Honda Hanako 本田華子
Anime: Asobi Asobase あそびあそばせ (Episode 4)

Character: Excel エクセル
Anime: Excel♥Saga, エクセル♥サーガ (Episode 1)

Character: Kronk
Anime: The Emperor's New Groove (Movie)

• {kata ni noru} tenshi to akuma
  肩に乗る天使と悪魔
  The angel and demon [that] {ride [someone's] shoulders}.

Other Internal Conflicts

In some cases, the conflict inside a character isn't between an evil devil and a good angel, but between other aspects of the character's personality.

Character: Shinomiya Kaguya 四宮かぐや
Anime: Kaguya-sama wa Kokurasetai? ~Tensai-Tachi no Ren'ai Zunousen~ かぐや様は告らせたい？～天才たちの恋愛頭脳戦～ (Season 2) (Episode 2)

• Context: calculating Kaguya vs. dumb Kaguya.

More complex cases feature multiple aspects of a character arguing with each other, rather than just two sides fighting.

Anime: Otome Game no Hametsu Flag Shika Nai Akuyaku Reijou ni Tensei Shiteshimatta…, 乙女ゲームの破滅フラグしかない悪役令嬢に転生してしまった… (Episode 1)

• Context: Katarina Claes カタリナ・クラエス convenes with herself to come up with an anti-BAD END strategy.
• Katarina nounai kaigi
  カタリナ脳内会議
  Katarina Intracerebral Council.
  Council Inside Katarina's Brain.
• gichou Katarina
  議長カタリナ
  Katarina council-president. (chairwoman.)
• tsuyoki Katarina
  強気カタリナ
  Strong-willed Katarina.
• yowaki katarina
  弱気カタリナ
  Weak-willed Katarina.
• happii Katarina
  ハッピーカタリナ
  Happy Katarina.
• majime Katarina
  真面目カタリナ
  Serious Katarina.