The Aishi Condition

The Aishi Condition is a name coined by The X Group to describe an incurable genetic-mental condition in the Yandere Simulator and YanderX worlds. The condition can not be contracted by anyone other than an Aishi Child, as it is passed down from Aishi mother to Aishi child.

Potential Origins
Although no-one apart from the Aishis knows the origin, There are a few theories as to what caused the genetic condition (created by The X Group).

The first theory is that The Aishi Condition was created due to severe trauma and loss to the first Aishi, as that is how Dan Smith lost most of his emotions.

The second theory is that the condition could have been contracted normally in the early stages of civilization, but the condition was (mostly) wiped out and the Aishis are the only bloodline that has it.

Effects
All Aishi children lack the capacity to feel emotions, listen to music, see beauty and feel warmth, until encountering a 'Senpai', though Aishis can feel pity, at least towards specific people before encountering a "Senpai". All Aishis seems to have increased strength.

Strangely enough, the condition seems to have altered their DNA by only allowing the Aishis to have daughters, and not sons (or at least made the Aishis having male children rare), though that is currently speculation.

The Aishi Condition has forced the Aishis to become Yanderes, an Anime term describing characters (mostly females) who will kill to protect their romantic partners. (in some cases however, Yanderes kill the lovers themselves due to the them being attracted to [or cheating on them with] other females, though this is not the case here.)

Counter-Condition?
There is evidence to suggest that a counter-condition exists, allowing the Aishis to feel emotions, listen to music, see beauty, and feel warmth. It's currently unknown what allows people to develop this counter-condition, but it only seems to develop in Japanese males, or those with Japanese decent. This condition may begin to manifest at random, or at a specific age, although all people with the Aishi Counter-Condition have had it manifested by age 18.

People With The Counter-Condition

 * Ayano Aishi's Father
 * Taro Yamada
 * unknown 3rd person