Spring. Far from the city, time flows peacefully in this rural town. As the cherry blossoms scatter in the wind, a young man named Yu Narukami steps off the train at Yasoinaba Station. Yu has come to this town, where his uncle lives, for family reasons; he will be transferring into the local high school, Yasogami High. And so begins his school life... The shopping mall after school. A series of murders taking place in town. The Midnight Channel, airing late at night.... What lies in store for Yu and his friends ‘this time around? (Source: Aniplex USA)

Each episode follows Fukuzou Moguro, a traveling salesman, and his current customer. Moguro deals in things that give his customers their heart's desire, and once his deals are made and their unhealthy desires are satisfied, Moguro's customers are often left with terrible repercussions, especially if they break the rules of his deals...

The world is a dark, brooding place populated by humans, but ruled in reality by powerful beings known as the Darkstalkers, and there is constant conflict between them as they try to determine who is the most powerful of them all. Zombies, vampires, werewolves - all of them compete in contests of strength and sheer will to attain their own personal goals. All of this becomes moot when a race of Aztec robots called the Huitzil decide that humanity isn't worth saving, and start waging war on the world, while in the sky, a solar god from outer space plots the conquest of Earth. And the Darkstalkers must become unwilling allies in order to save the world.

Marin and her younger sister Urin are seafolk who happen upon something quite strange: a beautiful silver ring lost beneath the waves. The kind-hearted Marin, intent on returning it to its owner, drags a reluctant Urin along with her to the sky world despite reminders of a turtle elder who left for the surface and never returned. After locating the ring's owner, Kanon Miyamori, they learn that Kanon had tossed it into the sea after her boyfriend dumped her earlier that day. Though Marin insists that such a lovely item should not be thrown away, Kanon discards it once again. As they search for the ring, Urin becomes separated from the other two and accidently breaks the seal on a stone coffin, releasing an evil being known as Sedna. Sensing Sedna's release, the formerly missing turtle elder, Matsumoto, reveals himself to Kanon and her companions, naming Marin as the Priestess of the Sea. Together with the Priestess of the Sky, she has the power to seal Sedna away again. And as luck would have it, during an encounter with one of Sedna's minions, Kanon discovers that she is the Priestess of the Sky. Though Kanon is hesitant, she and Marin decide to work together to save the world from the evil that threatens it.