Yurikago is one of my favorite VNs.  That isn't because it so 'awesome' or a kamige.  Story-wise, it is actually a bit below the average for Akatsuki Works.  No, the reason I like this game so much is the characters and their interactions.

Kiritooshi Hiro, the protagonist (his surname means 'to cut all the way through' lol) is a young high school student who lives every day trapped in a web of his own apathy.  Tormented by his 'Knight Frame' (a magitech-type device that replaces his entire skeletal system) and a sense of his own guilt for having murdered his father in order to gain it (this is not a spoiler, it mentions this within the first fifty lines, lol), he feels isolated from the world around him, and he can only really consider those who are - like him - outside the norm to be people (this is a psychological disease created by the implantation of the Knight Frame into a psychologically immature subject).  He regularly attends a the Kurohagi Dojo, where he fights with Kangasa Ume, who has inherited an 'unbreakable body' (literally unbreakable... if she falls from the stratosphere, she is unharmed, but she is not invulnerable to disease or techniques that overwrite her original state).  He generally spends a great deal of time trying to defend himself (unsuccessfully) from the females of the story, who seem to vary from seeing him as a favorite chew toy to being eternally exasperated by him.  He has a bad habit of saying what he is thinking at any given moment in his rare interpersonal reactions, then wanting to bash his head into the nearest wall in embarrassment after reflecting on what he said.  When his few truly 'sensitive' spots are touched, he can instantly become a psychopathic, remorseless killer, but those points are relatively few and far between.

Kangasa Ume is the last survivor of the Kangasa Family, who all possessed an unbreakable body.   Her body imposes on her a unique and distasteful way of viewing the world, where her reactions to everything around her are determined on whether they are fragile or difficult to break.  She also despises that part of herself intensely, even to th point of being nearly suicidal at times.  With those few she allows herself to become close to, beating on them becomes a form of interpersonal communication (she regularly breaks Hiro's bones when embarrassed or irritated).   She is a student of the Kurohagi style, which focuses on the forceful creation of 'tenketsu' (breaking points) or the use of existing ones to destroy the bodies of their opponents.  She is fairly advanced in this, and as a kindergartner she once launched herself into the stratosphere when she tried to kill the planet that way.

Tae is the main heroine of the story and an angel.  Angels in this story are summoned into the body of a corpse from a higher realm and are bound to the one who loved the original owner of that body.  By instinct, they love their summoner/controller, and will do anything for his sake, up to and including self-harm or mass murder.  Since her kind were originally created as a slave race, she has an M streak a mile wide when it comes to Hiro, and she wants nothing more than for him to treat her like garbage and beat the shit out of her... and is unsatisfied that he doesn't do so. 

Aria is the last of the three heroines, a young angel who possesses wings made up of iron stakes and whose special ability allows her to overwrite the reality of anything she touches to have already been punctured by one of her stakes.  She is very honest and straightforward, a total innocent when it comes to everyday reactions and concepts, and (in her route) she is constantly asking questions, because she is also too intellectually lazy to think things out on her own.  She is also a drug addict, due to an existing command from her master that she use a certain drug to eliminate her emotions when they go beyond a certain peak level.

Kurohagi Zenjirou is Ume's adoptive father/grandfather and the master of the Kurohagi Dojo.  At one point, he was involved in the religious wars that resulted in the creation of the mystic technology behind the Kishi Kokkaku and angels like Tae, but he is now very much retired.  Despite his easygoing attitude, he regularly breaks his best students' bones and will even maim them if he thinks that is what is needed to train them.  He loves Ume deeply, but he believes in standing back and letting the younger generation find its own way.  He isn't really human anymore (psychologically or physically), and after two hundred years of life, even he admits he doesn't really understand people viscerally anymore. 

Tsugumu is an ancient angel (the  most powerful one) who performed the surgery to transfer Hiro's father's Knight Frame to him after Hiro killed him.  She loves anything interesting, and she sees her abandonment by her master as a very long-term sexual play.  She, like all the other women around Hiro, regularly beats the shit out of him for minor infractions (either through teasing or literal blows), but she seems to always be looking on the people around her from the outside.  She is very lazy and generally careless (she forgot to 'zip Hiro up' when she implanted the Knight Frame, which was a small part of the cause of his mental disorders, lol). 

Redear is the heroine of Tomoe's side-scenario, a psychopathic loli angel who skins people alive and removes their limbs and organs for fun.  She makes little sense when she talks, frequently referring to various fairy tales and old children's books, such as Allice in Wonderland.  It is impossible to tell what will make her happy at any given moment, but it is generally guaranteed to include killing someone or doing something similar.

Tomoe is a young man who acts entirely on impulse, living as he desires at any given moment.  When he sees bullying, he beats the shit out of the bullies, then he beats the shit out of the bullied one.  When someone mistakes him for a woman, he breaks their ribs and jaw, then leaves them for dead.... and when he meets Hiro, he always tries to cause a confrontation with him. 

Now, needless to say, the characters of this game are... unusual.  I loved their antics, and the game is pretty violent (think pulverized flesh, followed by repeated regeneration, followed by more pulverization).  The Grand Route is an excellent follow-up to the other routes, and I always leave this game feeling satisfied.

Edit:

For those who are interested in playing the game, there is a suggested (by me) playing order.  Generally speaking, you want to do Tae's route right before the Grand Route (because Tae's route is way too revealing).  This is immovable.  If you just want to see the true ending, do Tae's route and the Grand Route only, though you'll miss out on some awesome moments.  My suggested order is: Aria>Ume or Ritia/Tomoe>Tae>Grand Route.  Really, it would probably be best to do Ritia/Tomoe right before Tae's route, but if you want a bit of freedom of choice, that is a good place to put it.  I suggest Aria's route because it is the only route where most of the other characters are almost irrelevant and Aria is actually something other than a speechless killing machine.  It is also fairly revealing about how extreme the nature of the angels is, lol.

My favorite heroine in this game is Ume.  For all that she is the true heroine, Tae (or at least, the Tae in Tae's route) is mostly a do-M pervert who will do anything to get Hiro to smash her face in or treat her like dirt.  While she is pretty adorable in her route, Ume's internal conflict is a lot more interesting. 

The main reason that I say play Tae's route, even if you play none of the other heroine routes, is because Tae's route reveals several key elements about Hiro that are absolutely necessary for you to know in order to enjoy the Grand Route (really, it would be better if you knew stuff about Aria too, but meh).

The characters in this game, whether villain or protagonist side (note: everyone in this game is crazy on one level or another... hell, the most sane person there is Tae, and that is just... sad) are generally great... but moege lovers will probably run away from most of them screaming (Redear/Ritia is every lolicon's nightmare).  Ume is an extreme self-hating sadist, Tae is about as M as anyone can get (so much so that she can get off just on being ignored), and Aria is a drug addict... lol

Story-wise, the game is actually pretty good, but you should know that the writer chose to make Hiro an unreliable narrator and goes out of his way never to just come out and say things directly.  I love the setting in this game, and it was obviously designed to contain more than one story.  Unfortunately, Akatsuki Works Black produced three great games in a very short time and then got absorbed by Akabeisoft3, so we'll probably never see any more games in this particular universe... or in the Izuna Zanshinken universe (which, considering that the secret ending is open-ended, is sad).