Ryuukishi Bloody Saga might very well be the best unique work Akabei Soft 3 has created in the time since ABS2 forced a bunch of subsidiaries to merge to create it. It is a work I also come back to every few years simply because it holds a unique place in my heart.
Ryuukishi is the sequel to Ryakudatsusha no In'en, a Clock-up style super-violent H-horror VN written expressly for the purpose of setting up things for Ryuukishi. As such, to understand this VN, you have to understand the events of Ryakudatsusha, at least to some extent. Ryuukishi is written on the tacit understanding that you already know Roy's background, and there is little to no attempt to explain his personality or actions in the actual VN. Indeed, effort is made to keep you out of Roy's mind 90% of the time, with much of the story told from an unobtrusive 3rd person perspective.
For those who don't want to go through a Clock Up style experience, I'll explain the events in Ryakudatsusha (an outline) in the spoiler box below.
Roy was born the son of an apothecary in a small village that also had a minor drug production operation going on - though this is not said outright but rather implied. When he was eight or nine, his village was attacked by bandits, who promptly started raping and murdering the people of the village, torturing his sister in front of him in a way that is reminiscent of Maggots Baits. Unfortunately for him, the mistress/wife of the bandit leader took an interest in him, and he ended up her slave (sexual) for a large swathe of his childhood. At the same time, he met the daughter of the bandit leaders, a child of his own age that still had some fragile innocence left to her but was constantly being targeted by the indiscriminate bandits.
The girl became the only person he trusted even as he plotted revenge on the bandits, eventually becoming strong enough that he could participate in raids. During the raids, he usually made sure to kill anyone he met, so they wouldn't have to suffer, but the fact remains that he was constantly training himself to kill the entire time. However, when the bandit leader's daughter reached a certain age, things came to a head, and Roy set off his plan at about the same time. The bandits were killed, including the leader, but the daughter was gang-raped before that. Roy, answering her request, pierced her heart with his dagger, destroying the one thing of beauty he'd found in that dark place in his life.
While the time between Ryakudatsusha and Ryuukishi is something of a blank, comments in the story indicate he made a strong oath against killing people at some point.
The Ryuukishi setting is one closer to the Witcher than to the Lord of the Rings. Humans only kill those monsters that exist with great effort (though weaker ones like goblins can be beaten easily one on one), and it isn't uncommon for areas to be plagued by monster attacks, though this has apparently lessened in recent times, as methods of driving them away (through planting certain plants that repel monsters and such) have been established. On the other hand, magic seems to be fading to the point where most cities have never seen a magic-user and only know magical energy as a legend, even if they see monsters on a regular basis. Roy himself, despite being a traveler, has never seen magic or magical energy used, to give you a reference point.
Roy is working as a traveling apothecary when the story begins, arriving in Vilduun, a walled city constantly plagued by the attacks of a red dragon. Roy, being obsessed with helping others, promptly plies his trade without compensation for the people of the city in the wake of the most recent attack. This leads to him being invited to live in the knights' garrison even as he helps with reconstruction. He also finds himself being watched over by four female knights (yes, this is a true harem VN) who have varying degrees of interest in him, ranging from budding attraction the case of Saria to suspicion in the case of Lize.
Generally speaking, the story is somewhat slow early on, and there is no dramatic scene where Roy shows up the knights as you might expect in another fantasy action VN. Instead, Roy serves as a constant catalyst for change, as events slowly build up momentum. Later on, there are some excellent action scenes and CGs, but those really are late in the VN.
Story-wise, this most recent playthrough has shown me how clever the design of the scenario was. Relatively minor characters like the Vice-Commander Malter and the seeming weakest of the heroines, Lize often serve to move the story along and prevent any sense of monotony. The villain characters (yes they exist) serve as counterpoints to the more 'normal' people in the story and echo Roy's past.
In the end, Ryuukishi is a story of redemption, where a man with a tortures past and a constant smile breaks free from that past and becomes something better.