Setting: There is an unwritten rule somewhere in the world. When a person dies with unspoken regrets, the letters he failed to send during his lifetime will be delivered by a mysterious black cat.
Story: Chen Mo is a young man who is tired of life. One day, an elegant black cat jumped into his window sill with a letter in its mouth. As the "sender", he must follow the black cat through the streets of the city to find the mysterious recipient.
Intention: That late letter will eventually arrive where it should go with the warmth of time.