"After being badly wounded by Elsa, Subaru somehow survived and awoke in the mansion of Margrave Mathers, in the Kingdom of Lugunica.

Subaru now lives and works in Roswaal's mansion, working with Ram and Rem, and finally getting Emilia to agree to a date with him. But the day of their promised date never comes as Subaru keeps going back to the day he first awoke in the mansion. He's confused at the thought that he Returned by Death despite having no memory of experiencing anything deadly, but he's determined to repeat his previous actions up to the point of fulfilling his promise with Emilia."
It's a touchstone for determining 
if one is worthy of the throne.
إنّها معيارٌ لتحديد ما إن كان المرء
يستحقُّ اعتلاء العرش
Ob jemand für den Königssitz
geeignet ist oder nicht,
Es vital para determinar
si alguien es digno de tomar el trono.
Es vital para determinar
si alguien es digno de tomar el trono.
C’est une pierre de touche
qui permet de vérifier
È il simbolo che determina 
se una persona è adatta a salire al trono.
É um dos critérios para julgar se 
alguém é ou não digno do trono.
И позволяет определить, достоин ли 
человек права занимать трон Лугуники.