He is Pei Siyu, who uses his life to fulfill his promise to protect her; she is Gu Niannian, who spends the rest of her life waiting for the unfinished promise. A rare terminal illness caused his childhood sweetheart's love to stop in the middle of summer. He chose to continue his existence by donating his heart, allowing his younger brother to fulfill his vow to "enter college together and live a lifetime together." The ticket contains her longing across the mountains and seas, the sound of her heartbeat carries her worries across life and death, and the promise made under the old locust tree will eventually be fulfilled in two reincarnations.
Intention: A promise made in youth is worth more than a thousand pieces of gold, and the sincerity that runs in both directions has never faded even across life and death.