Shi Ran has had a secret crush for four whole years on her university senior, Qi Yan, the top star in the voice acting world. After graduation, she unexpectedly joins his studio, unaware that this reunion is the result of his long-planned wait. On the eve of a blind listening audition, Shi Ran discovers hundreds of recordings on his computer. For four years, he has recorded nightly voice diaries about her. From bringing her an umbrella on a rainy day to their first encounter on campus, every line is a confession he never dared to speak aloud. What she thought was unrequited love turns out to be years of silent devotion, with his voice keeping watch over her. As their breaths mingle into heartbeats before the microphone, and the recording button seals an eternal vow, she draws closer to him through her voice, and he answers her with the rest of his life.