Trait: Sanpaku Eyes
A character with this trait has Sanpaku eyes.
Sanpaku eyes refers to eyes in which the white space above or below the iris is visible.
In Japanese media, this is far more common in male characters than in females. Sanpaku-gan produces a more “piercing and sharp” look that lacks cuteness, so Japanese fiction tends to apply it to aggressive, delinquent, mean and/or rude characters.
Examples: 1, 2, 3, 4.