This is similar to the movie

"I promise I'll find you again, my love." He breathed. "I'll wait for you, no matter how long it takes." I whispered back with a tear escaping my eye. "'Till our next life, I love you my Juliet." He held onto my hand tightly. "I love you too, Romeo." We kissed for the final time. The both of us gripped onto our engraved rings along with our swords before stabbing it deep into our souls. ➺ Lucy Heartfilia, a princess from a fallen kingdom. When she arrived into the living world, a ring magically appeared on her ring finger with engraved words that spelled, "'Till death do us apart." Her parents tried to remove the ring, but it never budged. -- Natsu Dragneel, a young prince from a kingdom of dragons which also had the exact same ring stuck to his ring finger. The ring was unknown to the people to prevent disputes between royalty and their citizens. ➺ However, one day they met again. Here unfolds the tragedy of two lovers, their story has yet to begun. A NaLu FanFiction