Qi Luo, a high school computer science teacher, creates a personalized pixel game for his girlfriend, Bai Yuan. Every level is filled with little memories from their relationship. The game unexpectedly goes viral, attracting millions of players who follow their love story. Quietly refining his creation, he turns down commercial offers while secretly developing a special proposal chapter spanning 1,520 levels. On New Year's Day, he takes Bai Yuan on an offline journey through their shared memories and proposes to her in person. Having already seen through his intentions, Bai Yuan happily accepts and personally writes the game's ending. Millions of online viewers witness this tender love story of two people choosing each other, hidden within lines of code.