勾玉

1. Origins, structure, and basic meaning

• Structure: Written 勾玉 and read まがたま, it is an ancient curved, comma-shaped bead used as an ornament.
• Basic usage: It appears as a green artifact found at ruins and as a shape sketched in an exhibition hall.

2. Common pitfalls and similar expressions

• Curved form rather than round bead
  • Its distinctive bent profile sets it apart from an ordinary spherical bead.