Kuruma is a supernatural entity created by Yamari to watch over and spin the dharma-wheels.  He is constantly afflicted with ennui, a condition which was just recently cured by his new job.  Kuruma is not evil, though he is rather dry and somewhat bitter over his lot in existence.  He has never before formed a relationship with another sentient being, of any kind, and his social skills are miniscule.  Jewelry is one of his few true joys in life.
 

Sattva is the soul currently under Kuruma's rule--er, protection.  Upon meeting him, she requests that she retain her name in whatever life he gives her.  Her personality is retained as well, though everything else (including her gender) is subject to change.  Sattva is an optimistic, mildly disturbing person; she is as fascinated by gore as by the latest fashion accessory.  Her sense of humor is rather morbid but she's not usually angsty.  The sudden change Kuruma brought into her existence jarred her somewhat, but she thinks she'd be able to deal with it better if Kuruma weren't so damn awkward and/or tactless about everything.  She is not a good person by any stretch of the imagination, but that's probably one of the reasons why Kuruma was assigned to her, eh?
 

Yamari is the Tibetan protector of Buddhism. He likes it when people do what he says. Shortening his name to 'Yama' or even 'Yam' will result in a smiting of the highest order.

Sinclair always introduces himself as a humble businessman, though he is quite a  lot more than that.   He has an obsessive personality; he's ruthless, meticulous, and he loves to collect things.  Sinclair is -very- smart, and knows a little about a lot and a lot about a little, especially in his fields of interest.  But he'll collect anything that catches his eye--he actually has a fair amount of Beanie Babies (not that he'll ever admit to that, of course), even.  If he tires of it, he'll just sell it.

Mayavda is Sinclair's secretary, although he does a lot more than take memos (not like that, you perverts), such as corpse disposal and client intimidation. X3 However, Mayavada, like his name suggests, is not quite what he seems...
 

The drummer for Sattva's band in one of her incarnations.  Caring, sharp, and outspoken, Metea is differentiated from the other bit players in Sattva's lives because she actually seems to know something about Sattva's predicament...

NEMO:  First appeared here.  Nemo was a homeless waif that was eventually killed by Sinclair (though not before Sinclair fed him a lovely last meal).  Like Sinclair's other victims, Nemo's soul was extracted from his body and placed inside a crystal.  It was his dharma wheel that Sattva noticed as having stopped.  However, by the time she noticed, the crystal had already been sold.  Since Sinclair's crystals are quite fragile, it did not take long for the crystal to shatter and the wheel's movement to resume.  

NATHANIEL: Called 'Ni.'  The keyboardist for Thanatos, Ni paints his face like a clown and goes onstage shirtless for performances, but in actuality he wears glasses and is fond of cardigans.  His vision is extremely poor, but he's able to get away without his glasses on stage (his eyes are too sensitive for contacts) because of his detailed knowledge of his equipment.  Ni is bright and kind, but sometimes not terribly aware of the world around him.

GABRIEL: The guitarist and backup singer for Thanatos.  Gabriel likes to wear the strangest combinations of clothing possible, such as vests over sheer, skintight shirts.  He often wears a cross because he and his family are devoted Catholics (he has five brothers and sisters), but despite (or perhaps because of) his strong beliefs he is very tolerant of other ideas.  Easygoing but observant, Gabriel tends to become aggravated mostly by Sattva's telepathic talks with Kuruma--again, despite his religious beliefs, he is a realist, and finds Sattva's mutterings  to his 'muse' somewhat disturbing.