Forehead Shadow

In manga and anime, sometimes a shadow is drawn over the character's forehead, covering their eyes and going all the way to their nose. This shadow appears out of nowhere, regardless of the illumination of the scene.

It's a symbol to represent the character's mental state, and may be used when they're angry, devious, terrified, disgusted, among other situations.

In some cases, only the eyes or the nose is shadowed. In other cases, the forehead is drawn blue instead.

Fujioka Haruhi 藤岡ハルヒ, example of "anger mark," ikari maaku 怒りマーク.

Character: Fujioka Haruhi 藤岡ハルヒ
Anime: Ouran High School Host Club, Ouran Koukou Hosuto-Bu 桜蘭高校ホスト部 (Episode 10)

Usage
Examples
- Anger
- Disgust
- Fear
- Shock
- Despondency
- Deviousness

Usage

The forehead shadow can be used to represent various sorts of negative mental states, for various reasons.

The shadow can mean someone is depressed or feels down. In this case, people tend to literally look down, towards the ground, so assuming the light is above them, their face naturally becomes shaded.

Of course, as a symbol, there's no indication that the character has moved their head at all, the shadow simply appears.

Other emotions, like anger and disgust, tend to be accompanied by facial expressions featuring frowning which creates wrinkles between the eyebrows and on the nose. Instead of being drawn realistically, the wrinkles are simplified into shadowed areas.

Sometimes, blue lines are drawn across the nose to symbolize those wrinkles.

Shadows are often drawn blue when a character feels unwell. That's because, when referring to the color of the face, blue in Japanese means the same thing as pale in English, so a face turning blue in anime means the same thing as a face turning pale.

The shadow is blue, then, when the character's blood pressure drops, when they're sweating cold, when they're in shock, and so on.

Shadows are also drawn in characters that feel anxious, nervous or tense. And in characters that appear despondent, in despair, or otherwise mentally unwell. Including those that have murderous intent.