Welcome to the world or Ar Tonelico! For those of you with an actual background in the history, the setting, the game, the... Anything... Forget it! It shall all be horribly bastardized for our entertainment.
The basic concept is this: The characters make up a group of wandering... Eh, general purpose do-gooders, as monsters are quite common around cities, and though most of them are easily driven off, more powerful ones can present an extensive danger to the city's livlihood and the people who live there. It is a common practice to hire mercenaries and the like, but when people are in real trouble, these mercenaries charge exhorbitant fees. Being, generally, decent people, you offer help at whatever the people of the town can afford. Sometimes it might just be a few meals and an Inn stay, but all in all, it's good work, and it makes you all quite popular.
Things peculiar about this world: Predominantly a mid-to-low tech setting, there are rather arcane airships, and the occasional gun or other strange bit of technology. Honestly, the basis is more a mid-to-high tech super science setting, but the characters interact in a more fuedal, lower-tech sort of way.
The other primary pecularity of the setting are the Reyvateils. They look more or less exactly like humans, and are strictly female. They have undergone a special form of bioengineering to let them commune with a partner and unleash magical songs. They are physically more fragile, particularly compared with the downright heroic durability that other combatants can have, but their song magic is one of the most powerful forces in setting, capable of creating massive blasts of energy to smite their foes, or waves of healing to support their allies. Unfortunately, these songs can take quite a bit of time to cast, so the rest of the group must shield the Reyvateils from harm and distraction.
A Reyvateil discovers more songs through the process of "Diving" which, within the original setting, is alluded to and treated much like sex. For purposes of the perversity of the Bedroom forum, it will be sex. When a Reyvateil has sex their minds and the mind of their partner come close together, allowing the partner to help the Reyvateil create new spell songs. This creates a deep bond between the two. Unlike in the game, a male is expected to bond only with one female, Reyvateil or otherwise. A warrior with a Reyvateil is very alluring to some women, though, so seduction attempts are... Common. Some men even get away with it, particularly at lower levels of bonding, but not if they climax within the female. Further, as Reyvateils and their partners are the most potent method of fighting monsters and demons, a rather intellegent breed of succubus have arose who are more than willing to quite... Physically seduce males. Most of them are relatively resistant or impervious to physical harm, and it is told that if they can be made to climax they will become docile, but it is quite a distraction to a Reyvateil to see her chosen partner with another woman's lips wrapped around his dick, and destroyes their cocentration completely if he... Loses it to the charming demon... It doesn't help that the link causes them to share feelings of pleasure and pain.
Still, adventure, and perhaps pleasure, await those who venture within this realm...
A further note on Diving: Now then, it have made some vague allusions to it, but although Diving does require sex, not all sex is diving. A Reyvatiel does, instinctively, try to cause a Dive if it's been... Too long, and even more strongly on he first time. Regardless of this, little bits of the mental connection flow through even in a non-dive, meaning that a male will always be quite aware when he is... Enjoying a Reyvatiel. As a note, the Reyvatiel's body actually gives off small amounts of energy during a Dive, and while this does not harm the male in any way, it does, quite adequately, prevent pregnancy. In any case, during a Dive, the male's mind enters the females, seeing all of her her conscious and subconscious are willing to show. While in this state, he may interact with an interior version of herself, one some might say is truer, but in any case one which has the Reyvatiel's emotions and, ah... Emotional problems much more strongly. In any case, it is using the Reyvatiel's history and experiences, guided by the male, that this inner self creates new spells. Traumas and other things tend to create roadblocks to this process, as does the fact that within a human or Reyvatiel's heart and mind there are always ugly things that one does not wish to share with others. Only by overcoming these roadblocks can more powerful spells be created between the two, but they have a limited amount of time, as while they work in the mind, their bodies continue to copulate, and once climax is reached, the Dive ends.
I except this could contain pleanty of consensual sex, with whatever kinks those involved would like to deal with, as well as some seduction, and very likely rape. I am willing to run this as both a larger group thing or as a smaller side thing, more one-on-one and such.