I have no idea what you're referencing
VTM stands for Vampire the Masquerade, which is a 90s tabletop roleplaying game where you play as vampires, or Kindred.
The first vampire was Caine, whom God cursed for killing his brother, Abel. In order for the curse to be passed down, a vampire has to completely drain a human of blood, and then give them a bit of their own blood in exchange. I don't want to know exactly how Alex envisions the Aishi Condition™ to be passed down, and tbh I don't want to know specifics, but knowing him it's probably something perverted.
Caine was a generation 1 vampire, and he made several other vampires, who are generation 2. The gen 2s made the gen 3s and so forth,. The newer the generation, the farther they are from Caine, and so their blood is more diluted, meaning they aren't as powerful, but also their weaknesses aren't as pronounced.
Compared to Alex' world, 1800s Aishis are basically emotionless husks, while current day Aishis can have feelings beyond Senpai Infatuation, Single-minded Jealousy and Murderous Rage. Except Ayano and
Luna her Cousin, ofc, because they're speshul like that. In both settings (can we even call YanSim a setting? I mean, we have a lot of superfluous lore, like that magical girl pretty mizuki anime, and the aishi curse, and shit) we see a decrease in the curse/condition's potency the higher the generation is.
Also, the Masquerade in the title refers to a loose set of rules to prevent humanity at large from finding out about the existence of vampires, because if they did, it would be a guaranteed death sentence for every bloodsucker on earth. Additionally, all vampires have a certain amount of Humanity, depending on how close they are to their former self, or to the Beast which lurks in every Cainite. Despite all of them being monsters, the high Humanity ones try not to fully drain the humans they feed off, and will only kill in the most extreme of circumstances, while the low humanity ones are so debauched they are essentially feral animals, and are hunted down even by their own kin.
Now, look at the Aishi, despite most of them being murderers, a lot of them still try to not kill unless necessary, while Ayano's Cousin is a psychopath who murders over petty shit, hence my comment about her being a low-humanity vamp. Again, in both settings, individuals afflicted by the curse appear to try to follow a moral compass so they don't get into trouble or worsen their condition.
TL;DR:
my schizo theory isAlex heard about Bloodlines 2 coming out sometime this year, found his way to the White Wolf wiki, copy/pasted the Vampire entry, word replaced "vampire" with "Aishi" and "blood" with "cum" and that's how he got the lore for the Aishi Condition™.
Leaked picture of Alex coming up with Aishi lore.
As an aside, in VTM there is a thing called Diablerie, which is the only way for a vampire to decrease their generation and it is done by fully drinking the blood a vampire of a lower generation (a 7th gen fully drinking the blood of a 5th gen becomes 5th gen). I hope that Alex plans for such a lore tidbit, and will leave it to him to decide what exctly it would entail for an Aishi to decrease her generation.
Apologies for the autistic sperging about an IP that nobody has really cared about since the mid 2000s, I just found the similarities a bit too similar.