Ruan Xing, an illustrator suffering from insomnia and anxiety, and Shen Shi, who works in high-pressure exploration, each use the same sleep aid app, Starry Sea. The two accidentally stumble into an overlapping psychological imagery space, traveling together through mountains and seas, both thinking the other is merely their own fantasy. As clues for the art exhibition emerge, the two rush to the real-life art exhibition to meet, only to discover that they are actually childhood neighbors who had been separated for many years. Spanning the two-way journey between dream and reality, it hides the bond of childhood old times. When the illusion falls, can they in reality firmly grasp this predestined relationship?