Update: added new characters and two new plots
A Hero is Only as Good as Their Weapon (Futa x Male/Female
In the near future the floodgates to the supernatural world have been blasted open, causing all manner of terrors to flood into the human world. Monsters, demons, evil spirits who posses the innocent to commit their wicked acts, all of these things once legend have now become a daily reality. However, while conventional weaponry can only do so much to hold back the darkness, with the rising supernatural presence in our world humans across the globe have begun awakening to their own magical potential, hidden dormant within the human race for so long. Special task forces of magical soldiers have risen up to combat these new foes, and schools all across the world have opened to train the next generation of youths to keep up the seemingly never ending fight.
Hope-field's Supernatural Defense Academy is one such school, specializing in the practice of "Arms Melding". Arms Melding is a technique in which two students form a close pairing, the "Arm" using transformation magic to manifest themselves as a weapon that their "Wielder" then uses in combat, the two partners synergizing and combining their strength into a single, powerful fighting unit. The full inner workings of Arms Melding is as of yet not fully known, though when two people with the potential to become a team come into close contact, their mana and souls temporarily merge and form an almost unbreakable bond, and the school exists to cultivate and trigger the creation of these bonds.
Oddly enough it has been observed that exclusively women end up being Wielders, and the grand majority of Arms are men (though there have been a few recorded cases of women becoming Arms). When two people become bonded they start to undergo various changes: women will gain massive boosts to their physical attributes, becoming stronger, faster, more durable than normal humans, making them better fit to wield their Arms, while the Arm will gain a significant boost to their magical ability. Wielders will also slowly become more aggressive, combative, and in some cases domineering, while Arms will conversely start to develop more passive, submissive traits. The changes are even physical, Wielders reporting a noticeable growth spurt right after bonding, while Arms will at times loose muscle mass and take on softer, more slender features (bordering on full on feminization at times). The extent of these changes all vary from person to person, however what doesn't vary is that shortly after bonding the new Wielder will grow a full working set of male genitalia, and an increased libido to match.
Due to the intimate nature of bonding, and a Wielder's increased libido, romantic/sexual relationships between pairings are common. It has been observed that emotional and physical intimacy between partners increases their "Synchronization Rate", more closely linking their souls and improving their efficiency in combat. Because of this fraternization between students isn't prohibited at the school, in fact it is encouraged so that partners can be as powerful and effective as possible, the school even going so far as to provide special classes to teach Arms how to properly satisfy their Wielder's unique sexual needs.
The rp would focus on the relationship of one such pairing, from the moment they are first bonded, to their exploits training and fighting various monsters, to the development of their relationship. The setting naturally lends itself well to a more femdom scenario, but it isn't a necessary kink or theme. While the bonding process may steer a Wielder towards being dominant and an Arm towards being submissive, this isn't always the case, and the types of relationships partners find themselves in are often just as unique as the weapons they manifest into. In addition to scenes between the partners themselves, there's also options to get involved with other Wielders and their Arms, as well as the occasional scene with a monster who manages to get the upper hand on our heroes and have their way with them.
Fairwater's Revolutionary Breeding Program (Futa x Female, NC, group)
Over the years Japan has made many attempts to combat it's declining birth rate. From breeding a culture that encourages early marriage, to tax incentives for couples who bare children, to even subtle, conspiracy level things like heavily censoring pornography so that young people will feel encouraged to go out and see the real thing. None have worked particularly well, and the country faced a slowly rising crisis few countries have ever truly faced before. As such a drastic new program was put into place, a mandatory breeding clause as part of all high-school attendance. Implemented several years ago across various coed schools, the policy was simple: all female students were required to become pregnant, and all male students were given free reign to have sex with girls as much as they wanted to accomplish it. Under this rule female students were not allowed to deny any sexual request or demand, and their continued enrollment in the school was considered legal consent for the boys to do whatever they wished with them. The only way to escape becoming a sexual plaything was to get impregnated and have said pregnancy confirmed by the school, at which point the girl would be exempt from the program and be allowed to return to normal study.
For some schools this policy was implemented quite well: established couples lead the charge to set a good example, boys behaved kindly and professionally in approaching girls they wanted to copulate with, and within a few weeks most girls were confirmed pregnant and were able to continue on with their lives promptly. Other schools however became absolute horror shows, with gangs of boys using and abusing female students, day long orgies replacing all school activities, and boys employing various shady methods to ensure girls wouldn't actually get pregnant so that they could keep them as sex slaves for as long as they wanted. As the program spread across the country the birthrate skyrocketed...but so did the enrollment into all girl's schools, female students flocking to them like crazy in search of sanctuary from the program. Though this mass of applicants drove up tuition costs and enrollment standards of such schools so high that only the brightest and the richest elite could afford the safety of an all girl's school.
Fairwater's School for Young Maidens is one such elite school, a pristine, radiant haven where girls from all over the country can come and live out their school days without worry for the crazy breeding programs sweeping the nation. However this school technically is not a proper "all girls" school, for it is one of the few girls academies that allows in futanari, and was in fact opened specifically to be a place where such women could fit in and belong. At first this didn't really prove an issue, some slight paranoia from girls who had escaped from particularly depraved schools, but nothing that really caused a divide in the student body. That was, however, until the new student council president was elected, an ambitious futa who saw the school not as a haven for young girls to escape the breeding programs, but a treasure trove of the most beautiful, affluent women across the country. The way she saw it, to allow such women to escape passing on their immaculate genes just because of their ability to buy their way into the school was a travesty, a mockery of what the entire program was trying to achieve, and an insult to all the women who had toughened it out and complied with the program regardless of their personal feelings. She saw those women as heroes who made a great sacrifice to protect the future of Japan, and all the women who safely roamed the halls of Fairwater as cowards who were too afraid to do what was best for their country.
As such the new student council president spent many weeks appealing to the school board, until she finally managed to get them to approve her proposal, Fairwater's own version of the breeding program. It was the coed school program's equal in every way, except instead of giving the power to men to breed with whatever girl they pleased, it would be the school's futas who would be allowed to run rampant. The day of the assembly where the new program was announced was a shocking moment for all, and it was quickly discovered just how much darkness truly resided within the school, lying beneath the surface of being a girl's paradise. All at once everything was unleashed, pent up desires and frustrations, feelings of love, hate, jealousy, lust, all came pouring out at once. Futas began turning on and raping their most trusted friends, girls who had been part of a group of futa classmates suddenly found themselves a toy being casually passed around, star athletes of the sports clubs found themselves the new team cumdumpster, girls began desperately bargaining to be "protected" and "claimed" by a single futa lover rather than be subjected to the hordes of their horny classmates, futas with particularly desirable girlfriends began to "sell" the chance to have sex with them, lesbian couples found themselves watching in horror as they were torn apart and violated in front of each other.
How does one survive in this former paradise now turned perverse prison? There are various different set ups for this game. Perhaps following a young couple or group of friends as they try to survive the school's crazy new policy. There could be a GM situation where on person is controlling a bunch of different futas as the other plays a girl being passed around from place to place. Or we could do an "anthology" style approach, doing various scenes of different characters, showing how the new program has affected them.