Angel No. 444" is the story of a celestial being sent by God to oversee and control the life of Thi, a human who sees the world upside down. However, as time passes, the angel forms a deep bond with Thi, which leads him to question the very purpose of human existence—especially when every life inevitably ends in death. Ultimately, Angel 444 chooses to let Thi take control of her own destiny, in a journey to discover the true meaning of being alive.