One is a male entrepreneur in the e-commerce industry who has been brainwashed by success studies, and the other is an introverted female designer with a craftsman mentality. When the mysterious Comet 666 passes by the earth, the fate of the two intersects because of a fashion live broadcast and an accident in a pet hospital. From then on, once the two feel unhappy, their behavior will become very similar to each other's pets. This marriage arranged by the universe of "you are in me, I am in you" is sometimes a surprise, sometimes a trouble, and it is also an opportunity for growth and love. The dog-like girl and the cat-like boy experience the joys and sorrows of life together, and become better versions of themselves. Perhaps, compared to the Comet 666, love and dreams are the greatest miracles in ordinary life.