This is my fourth time replaying the Light VN, Vermilion Bind of Blood, and to my startlement, I realized that my only commentary on this is is in my ancient VN of the Month Thread on the forums.  So... of course I cannot leave my beloved public ignorant of this game (though I've made a habit of recommending it to everyone, like Evolimit).

Vermilion was the first chuunige made by Light's second team, and it was my first experience of the team's work.  It is also probably that team's single most balanced VN, and it is the only one I call a kamige, albeit with a few reservations. 

The protagonist of this story is one Kashima Toshirou (who is referred to in the Western fashion as Toshirou Kashima throughout the whole game).  He is a former samurai from the era just before the opening up of Japan by Perry's black ships who became a vampire.  Now he is a gloomy man who serves as a watcher for the vampiric community of the fictional American city of Foggy Bottom.  Toshirou is something of an anomaly amongst vampires in general... and most seem to hate him instinctively (there is good reason for this, though few ever know it).  He considers all vampires merely to be an extension of humans, denying the vampire legend that most believe in, and he has nothing but contempt for those who allow themselves to drown in their power and the arrogance born from it.

This game has four heroines.  They are:

Anne Portman- The first heroine.  You are forced to play her route first (probably because nobody would want to go after her if given a choice).  Unlike the other heroines, who are more or less easy with their lives as vampires, Anne is a timid, kind-hearted girl who is fundamentally unsuited to being a vampire.  Her role in this game is quite similar to that of Kasumi in Dies Irae (more as a contrast in the form of a 'normal person' than as a real heroine).  While her character is less than inspiring (that she is a heroine is the only flaw I see in this game), her path is actually quite good, though less so than the others in this game.  I did and do find the ending worthy of mention, because it is... pleasant in a sad sort of way.  It is also surprisingly uplifting, coming back without being tainted by my dislike for the presence of a Victim A heroine in a chuunige VN.

Sherryl McGregor- The victor of the heroine polls twice in a row, Sherryl is Toshirou's long-standing partner in both work and the home.  Their relationship is a 'don't ask, don't tell' one where they don't talk about their pasts.  It is an easygoing relationship, but it is fairly obvious that Sherryl fell for him decades ago.  If I were to compare Sherryl to a translated VN heroine, it would be the adult Cal Devens from Phantom of Inferno, albeit with a century and a half of experience under her belt.  Sherryl was born in Victorian England, and her experiences in the slums there shaped her base personality.  She bluffs, she fights, and she has a temper... but underneath it all, she is as soft as a fuzzy teddy bear when it comes to Toshirou.  She is also a talented singer, a skill she shows off at Casanova, the bar near the office.  Her path is the most revealing of Toshirou's past (in fact, that is its structural purpose, though that doesn't interfere with its quality), and it is a fun ride...  Her ending is actually pretty hilarious as well as touching, because it is probably the only path in the game where Toshirou manages to move on to some extent (Toshirou is very very stuck in his ways).  Sherryl also grows a great deal as a character in this path (as a matter of course) and it is a pleasure to watch.

Nina Orlok- The Principal (political leader of a Diaspora, which is the name given to vampiric communities) of the Western US Diaspora, a young woman forced into a position far beyond her personal power by her powerful blood father's will after his death.  She sees her duty as the only way to repay her father's trust in her, and she constantly struggles with the gap between what she wants to be and who she actually is.  That said, she is actually a quite capable political leader (a given, since she isn't dead or imprisoned, despite being a youngling in a position that would normally only be allowed to an ancient vampire), with a core of strength hidden under the girl struggling desperately to fulfill her father's hopes.  I sincerely enjoy her path, each time, because her growth as a character is inspiring, especially once she gets past her father complex.  Toshirou in her path is probably the most samurai-like (in the classic sense), and the battle that closes out this path is the third-best in the VN (behind two of the fights in the Grand Route).

Ariya Takajou- The Jaeger (vampire hunter) White Pile's successor, who has come to Foggy Bottom specifically to hunt Toshirou Kashima.  Driven by her desire to prove herself and a latent fear born from her experiences as a child (her family killed before her eyes by vampires), she endured training that would make a Marine recruit run away screaming to obtain the ability to almost match the physical abilities of a vampire (it is something close to inner qigong).   She despises all vampires and sees them as inhuman monsters, but her meeting with Toshirou fills her with a personal hatred, as his obvious (to her) difference from other vampires drives her to obsess over him.  Ariya's personality (on the surface) is very... twisted.  She is probably the single most sharp-tongued heroine I've ever encountered (she makes Kagome from Comyu seem pleasant), quite naturally using insults in a tactical fashion to get vampires to lose their heads and simply because she doesn't like people.  In her own path, she also develops a rather... twisted sort of love for Toshirou (and it is love, mixed with hate, gratitude, and intense sado-masochistic lust).  I always rofl at the way she changes in this path, and the ending... is actually really really cool. 

Grand Route- The Grand Route of this game focuses on fighting the antagonist who was the root cause of the conflicts in the VN, as well as dealing with the origins of vampires in general.  In this path, Toshirou finds himself facing his past and looking into the future in a way he doesn't in the other paths.  This path also has two of the best fights in the game, including the final face-off between the antagonist and Toshirou himself.  This path also gives a really significant insight into the mind of a side-character whom I loved... Klaus, the previous White Pile.  The ending of this path is bittersweet and faintly sad (as is common in a lot of chuunige true endings), but it also gives you a sense of completeness, closing out the VN nicely.

Side-characters worthy of mention

Isaac- Isaac is the bartender at Casanova and plays a key role in all the paths.  He is Toshirou's one true friend, and his personality is a cross between a hedge philosopher and a boy who never gave up his dream (and never will).  His (oddly troubling) life advice frames a lot of the game's key internal conflicts, and his influence can be felt throughout every part of the game, to some degree.

Klaus- The previous White Pile, an elderly Jaeger who fights with a gigantic stake (think a log from a log cabin with its edges carved into a spike-like tip and you get the picture).  He is a warrior to the core, a man who hates vampires absolutely and has made a living sacrifice of his life to cleanse as many of them from the world as possible.  In contrast, his unstinting love for humanity, including its flaws, is awe-inspiring in its strength, and he has an absolute faith in humanity's potential to rise above its own filth.  He saved and raised Ariya to be his successor, and she is perhaps the only chink in his armor other than his personal hate (he normally sees vampires not as individuals but as harmful insects to be crushed) for Toshirou.  He loves her deeply, in a fatherly fashion, and it is his love that is perhaps Ariya's greatest salvation, though it is also her second greatest weakness.