Angel Sanctuary
Anime Info
This is a one-disc ova for the manga series of the same
name.  From the end of it, it looks like it will be
continued, but it never was.  You can read more of the
story in the manga, starting around "The Book of
Hades".  You find a synopsis of the first few volumes

The main plot revolves around Setsuna, a seemingly
normal teenage boy who goes to school with his best
friend, Akira, and who lives with his estranged mother
and dotes on his beautiful and perfectly sweet little
sister.  The problem is that he dotes on her a little too
much, and soon finds out that she returns the feelings.  
In the meanwhile, he finds out that there is an angel
sharing his body, a female who was once cast out of
heaven and sentenced to multiple reincarnations.  She's
also the target of angels and demons alike.  Rather than
deal with what's going on around him - which is so
complicated it even involves his former best friend and
protector - he elopes with his little sister and makes an
attempt at the perfect romance.  Just when things
couldn't get better, his guilt catches up to him and he
returns to face the mess he left behind.  Everything
gets worse from there.

You can find a nice review of the US released dvd
"A beautiful angel wages war against God - and loses.  Reborn as a human boy, Setsuna
struggles with horrific visions and supernatural powers.  Angels and demons flock to his
awakening, spoiling for battle.  Will Setsuna lead them to the apocalypse, or to salvation?"
~*~My Take~*~
This anime is a forbidden romance centered in the
middle of a backwards religious war.  The angels
are evil and the demons are good.  Incest is bad if
it's the angelic brother who wants his sister, but it's
okay if it's the angelic sister's spirit inside the
human brother who lusts for 'their' little sister.  
You never learn why the war that started
everything happened, or why the angels were
raping, pillaging, and massacring the poor
defenseless demons to the point where a high
ranking angel like Alexiel had to join the demon
side to defend them from her bretherin.  Rosiel,
Alexiel's misguided brother, seems to be a complete
nutcase.  You don't know if he was always that
way, or if his unrequited lust for his sister drove
him to insanity.

Alexiel ending up in the body of a human boy who
lusts for his little sister seems like karma
intentionally done to make her see how her brother
felt being on one side of a forbidden romance.  The
difference is Alexiel (through Setsuna) ends up
getting the sister to not only return the interest, but
to run away and have sex with her/him/them.  
Really a great snub at the traditional right and
wrong.  The romance in the anime is very tastefully
done, beautiful animation done very detailed so that
the forbidden love seems more heavenly than any
of the depictions of the angels.  Sarah (the innocent
little sister) is gorgeous, amazing hair, perfect
features that are so similar to her brother that they
might as well be twins, and a personality that could
be linked with Tohru (Fruits Basket) or Belldandy
(Ah My Goddess).  Everyone loves her because
she's perfect (aside from loving her brother too
Naturally this means she has no personality at all, but that just makes the animated romance scenes even prettier.  Like a
pretty bishounen with any unnamed pin-up girl, there's no way you can dislike the girl, so as long as you like the boy it's all
good.  Knowing there's a gorgeous woman sharing Setsuna's body probably makes the image even better for the guys.  
Note I'm not a guy.
Kira gets a good amount of screentime in the anime, and
he's the real reason I ended up buying the dvd after
renting it the first time.  His background in the anime is as
a 'sword' in the body of a boy who died - technically the
body is really that of Setsuna's best friend, Kira, but the
spirit in charge is not.  He's Alexiel's "sword", literally.  
He can't be killed, and although he does talk to the real
spirit of Kira (who never grew up and haunts him as an
unaging child), he seems like a normal teenager on the
outside.  He's made up a 'bad boy' image to keep his
estranged father away, to fulfill the trade he made with
the human Kira - that his father would not mourn when
he died.  The fact that he can't fulfill such a simple wish,
even with all his imortal experience, makes his character
more human.  The scenes with him and his father when
Setsuna is off floating around in his self-involved bubble,
actually made me cry.  I had no such reaction to Sarah's
angsty moments.  She never struck me as being as 'real'
as any of the others.
See more pics in the Angel Sanctuary Gallery; Kira's Page
Katan doesn't get nearly enough screentime.  He's clearly
devoted to Rosiel, even though he knows Rosiel has lost
it (if he ever had it).  He's more of a tragic character than
even Sarah - he never gets his one shining moment of
happiness before things go from bad to worse.  He's a
dedicated doormat, with just enough will to act on his
own when he's driven to it.

See more pics in the
Angel Sanctuary Gallery;
Katan's Page
Other fun little aspects of the
anime are the demons.  Two
crossdressing demons who are
looking for Alexiel's soul with
the hopes of reuniting her with
her body.  The little one, a girl
who dresses like a boy, and
the older one, a man who
dresses like a woman.  
Together they give a very
strange image of demonkind.  
If all demons are like them, it
really makes you wonder if
there wasn't a valid reason the
angels and demons didn't see
eye to eye.  Seriously, though,
they're straightforward
characters despite their
dressing habits.  The boy/girl's
dedication to Alexiel after
being saved during the war is
understandable, and I
sympathized with her when
Setsuna refused to.
I didn't get that close to the woman/man, but I appreciated his dedication to the younger demon (who appears to have a
very important role in the manga).  There's a scene where he hugs her to comfort her, and it struck me as more real and
tangible than any of the flowering romance scenes between Setsuna and Sarah.
Rosiel is just weird.  I didn't get
any sort of connection with him,
although the fangirl in me did
appreciate seeing him naked in
full angel-before-the-moonlight
glory.  I think he's there just to
torment Katan and to chase
after Setsuna/Alexiel.
We get a few embraces, some flirting (with both Setsuna/Alexiel and Kira), and a kiss that isn't really a kiss (with
Katan).  As far as the shounen ai (light yaoi) factor goes, the kiss involved tongue, so I guess that counts for
something.  He just looks too much like a woman, even with the nudity scene.  He reminds me most of Millefuille
(from Sorcerer Hunters).  Pretty bishonen are all good and well, but when they get that pretty you might as well give
them some breasts and call it a day.  We already have the incest, making it a yuri incest (sisters rather than
brother/sister) wouldn't make that much of a difference.