Yu Xi unexpectedly enters a deep-sea otherworld, becoming the surface-haughty yet inner-soft merman princess Xiruo, and partners with the cheerful and humorous system Qin Feng. To complete the return mission, she approaches the trapped dragon general Yunyuan. Choosing kindness time and time again, she quietly changes the established story, allowing the cold and guarded Yunyuan to believe in companionship once more. Amidst misunderstandings and trials, the three protect each other, jointly rediscovering the courage and power to choose their lives, and opening a warm new chapter spanning two worlds.