2500 years ago, in India, Siddhartha was born as a prince of the Shakya clan, but he gives up his position as a prince to see the world. While he travels he meets a strange boy named Assaji, who can predict the future and a monk with only one eye. Overwhelmed by the sufferings he witnesses around him, Siddhartha strives to restore peace. Meanwhile, Prince Ruri of Kosara begins his attack on the Shakya clan.

The fight has moved on to the next stage. A new plan is in motion... A new battle among the strongest warriors gathered across space and time has now begun!

10,000 years in the future, the world has become a very different place; monsters roam the land freely, and people, although equipped with high tech weapons and cybernetic horses, live a humble life more suited to centuries past. The story focuses on a small hamlet plagued by monster attacks and living under the shadow of rule by Count Magnus Lee, a powerful vampire lord who has ruled the land for thousands of years. When a young girl is bitten by the Count and chosen as his current plaything, she seeks out help of a quiet wandering stranger, D. It so happens that D is one of the world's best vampire hunters, and he takes it upon himself to cut through Magnus Lee's many minions, and put an end to the Count's rule.

There are some things that people are unable to say while they are alive; for these, there are "shigofumi," letters carried from the world of the dead to the world of the living. When a person with strong emotions dies, they are able to create a shigofumi, whether their feelings are of love, longing, or resentment. It is the quiet and mysterious Fumika's job to deliver these messages from the departed. Along with her talking magic staff Kanaka, she ensures that each shigofumi reaches its intended recipient, even if that person does not want to face its contents. Fumika witnesses the tragedies of people, both dead and alive, and sees their deepest secrets revealed. What is unclear, however, are the details of Fumika's past. Who was she before she came to be a carrier of shigofumi?