During the ruckus as the Kaginoji house, Nasa and Tsukasa pledge their love to each other at a church. After Nasa reports to Kaname that he has finally proposed, she points that he still doesn't have a ring. Although he doesn't take much notice at first, Nasa gradually becomes more self-consciousness about the role of a ring in newlywed life.
Certainly, a lower-quality diamond 
would be fine for a casual accessory...
...صحيح أنّ الألماس ذو الجودة المنخفضة سيكون جيّدا كزينة غير رسميّة
Für einfache Accessoires wären etwas
minderwertigere Diamanten sicher ausreichend,
En un accesorio se pueden usar
diamantes de menor calidad,
En un accesorio se pueden usar
diamantes de menor calidad,
Pour de petits bijoux, des diamants
de basse qualité conviennent très bien.
Certamente un diamante di qualità inferiore
 andrebbe bene come accessorio informale.
Um diamante de qualidade inferior certamente
seria ótimo para um acessório casual...
Безусловно, камни низкого качества
подойдут как простое украшение.