Manji is a samurai who's gone bad. For this reason, he's been afflicted with an odd form of immortality: although he can be killed any number of times, with all the accompanying agonies, he'll never actually die. His body, infested with odd symbiotic parasites called kessen chu (usually translated in the story as "sacred bloodworms"), will be knitted back together again each time. He's already started to see this for the curse it's meant to be.
Rin is a scrawny, passionate 16-year-old girl who's seen her father - an artist of the sword and master of a martial arts school - slaughtered and her mother raped and carried off. She's sworn vengeance on the perpetrators, the young master of a rival martial arts school and his followers. Although she's trained for two years to this end, her skills are still only basic, and in the meantime, her opponent's power has grown even greater. Her quest seems doomed to failure.
Manji comes to see Rin's mission as his salvation. If he can kill enough true villains while in service as her bodyguard, he will be free to die like anyone else. The result is a strangely satisfying partnership, and a story that I'm enjoying quite a bit.
I must note here that although the artwork is really great in this series - like that of Vagabond, it's more like conventional illustration than it is like manga - Samura presents rather more anatomical detail in his depictions of the bloody results of combat than do most mangaka whose work I've seen so far. This isn't a series for the faint of heart or the weak of stomach!
( Read on ... with spoilers )