The story is set in Edo's Fukagawa district, where the heroine, Oichi, dreams of becoming a doctor and assists her father, a physician named Shōan. Oichi possesses a special ability: she can hear the "voices" and see the "figures" of those who have passed away with unresolved regrets. With a cheerful and positive outlook, Oichi, together with a local police chief, delves into the darkness of human nature, solving mysteries along the way. While the story offers the thrill of a period mystery with unexpected culprits, it is also a coming-of-age tale of Oichi as she struggles and ultimately carves out her own path using her unique powers.