The Vow of Friendship, written in Italian, carved inside pocket watches that Giotto, and all of the First Generation Vongola Guardians possess, each with their respective Flame. For some reason, all of the watches appear to be stopped at 12:04.
In the Manga, behind the lid of Daemon's pocket watch doesn't have the vow engraved as in the Anime, instead there's a picture of Giotto and the other Guardians with Elena, Daemon's lover (Though, it's possible that the words might be covered by the photograph).
The pocket watches were given by Giotto himself and made by Talbot, a craftsman, when Giotto planned a secret dinner together for his Guardians, and were given during the dinner to celebrate their friendship.
- It says "Givro eterna amicizia," which means: "I swear eternal friendship."
- "Givro" stands for "Giuro," as v often stands for u in Latin or Ancient Italian.
- In the Drama CD, G. mentioned that beneath the cover of each watch engraved a message and a number. Giotto said that the numbers are based from the name "Primo" that given by his guardians. What the message and the numbers are yet to be revealed.
- It took three days for the pocket watches to be completed.