A square face has near-equal forehead, cheekbone, and jaw widths, with a jawline that drops in a defined angle. The hairline tends to be close to straight as well. The overall read is strong and decisive — many fashion-week models and male K-pop visuals share this shape, and it is highly photogenic.
The makeup goal is "soften the angles without erasing the charisma." If you fully round it out, you lose the signature look. Take just enough off the corners to make them feel polished rather than rigid.
For contour, work the corners — the jaw corners and the upper hairline corners. A small amount of shadow there softens the edges. Importantly: skip cheekbone contour. The square face is not horizontally wide at the cheekbones, so adding shadow there shrinks the face and weakens the impression instead of helping.
Hair-wise, soft waves and layered cuts work better than straight cuts. Long waves below the jawline help the angular jaw read smoother. A side-swept see-through fringe softens the straight forehead line. Avoid short blunt bobs — they push the angles harder.
For lips, soft curves work best — slightly overline the philtrum to add roundness. Place blush in a soft round shape on the upper cheekbone — that adds the curve the face is missing. Round, oval, or cat-eye glasses are the strongest contrast partner; square frames double down where you do not need to.