Based on a short story by Ken Liu, Arc is a story about a woman, Rina (Kyoko Yoshine), who has obtained immortality but struggles to find her place in the world and instead finds it crumbling.

In the near future, Rina lives as a wanderer, after leaving her child and home town at the age of seventeen. She then meets Ema, head of the BodyWerks division at Eternity, a major cosmetics corporation. BodyWerks are actual body sculptures of the deceased, preserved as if they were living, a technology that is available to the public to overcome their loss of their loved ones. Meanwhile, Ema's rebellious brother and brilliant scientist Amane begins research using this technology to stop aging among the living, granting them immortality. Through Ema and Amane, Rina gains new insights and embarks on a journey to become the first immortal in human history.—Arc Production Committee