Near a city, there is a well known cave. Unfortunately, due to budget constraint, the city government never tried to put it on use.
Now when they have some funds, there are suggestions to make the cave into a tourism object. But first, an exploration is needed to assess the cave if it can be used for tourist.
What the exploration team found inside are yukkuri. Not just normal yukkuri but House Yu or Minikkuri sized all white yukkuri. Even their accessories are white. Probably because of the light deprived environment, they also don't have any eyes. They're named Cave Yukkuri.
Specimen are taken to the Factory for research to see if they can be profitable.
Because the cave itself is dangerous, research is done in a simulated environment in the Factory itself. Lighting is no problem because the yukkuri don't have any eyes to know the difference from their natural environment.
Today is the presentation day.
Reimu (10), Marisa (12), Chen (8), Patchouli (9), Myon (10), all of them are ping pong sized adults. They gathered and sleep together.
A Reimu awake first and made her greeting. One by one the other yukkuri is awake. Then, with that first Reimu's lead, they make their Take It Easy greeting together.
Without eyes or light, they check the size of their group using the volume of this group greeting.
After that, they went in small group of 2 or 3 to hunt.
Focusing on a Reimu and Marisa pair. Both made low sound of "yu yu yu" and move forward. Without any eyes, they developed echolocating. But being paste brained, they needed 3 seconds to process the echo before walking about 10 cm. They also don't jump, only crawling carefully.
When researcher put a box as obstacle, they avoided it.
Next is food test. First, the researcher put Yukkuri Food: so-so taste. The Reimu first reached her tongue to it and bit. She said it's hard, so they will leave it for later. Next is Sweets Sweets taste. Same thing happened, the yukkuri left the food.
Last, the researcher tried a "poisonous" food, chili. Again, Reimu reached her tongue and tried a bite. This is soft, so they split it in two and start eating together clean and silently before proclaiming "Happyness~".
From this, it can be seen that unlike normal yukkuri who have sensitive sense of smell and taste towards food, these yukkuri has lost those sense. They don't react against sweets sweets.
Cave environment lack food, so the yukkuri adapt to this. They're able to eat anything, including spicy and bitter food. Also to not waste food, they will eat in "manner" that humans preferred, silently without scattering food around. Every piece of food is too precious to scatter around so they will bite it inside their mouth until the food is gone.
If there's any preference, it's in the texture and hardness of the food instead of the taste.
Other behaviour is when they are excreting. Cave yukkuri craved for companion, so they asked their partner to sing. While her partner is singing, they will go a little further and do poo poo.
Food are precious and cave yukkuri doesn't have any sense of taste and smell. They easily eat their own poo poo. The singing is also to keep their partner from listening to what they do.
After Marisa finished, Reimu asked Marisa to sing and she did the same thing.
Next, the researchers put 10 marshmallow. The yukkuri then ate all the Mister Soft Soft until their body turns to eggplant shape. White long thing with nothing but a mouth, really disgusting.
Abyuse group is already excited about this development.
Unfortunately, reality is different. Marisa and Reimu put the marshmallow on their head and they trace back the path they came from.
Cave yukkuri can remember the way they have walked from. But if they took it too easy, they will forget about it and never be able to came back home. Only fool will hog all the food and then got stranded forever.
At home, Reimu and Marisa is the first group to return.
In other place, Chen and Myon pair can't find anything to eat. They munch munch on the Unhappyness tasted hard rock and soil. Cave yukkuri can eat stone when they can't find any soft food.
To make them feel better, Chen and Myon rip a bit from their accessories to eat.
Unlike normal yukkuri who have sense of sight, Cave Yukkuri is not too persistent about their accessories. They recognize each others by their voice. For this, they can eat a little bit of their accessories to quell down feeling of uneasyness.
Back at their home, the clan do group greeting again to check their numbers.
Knowing Reimu and Marisa has eaten a lot and became big, the group asked them if they can start making Little Ones.
Reimu and Marisa refused, something unimaginable for normal yukkuri.
The herd then call both as scum who don't want to make little ones even after they grow big.
To the clan, Reimu and Marisa presented the leftover marshmallow they brought home.
There's a lot of Mister Soft Soft, but unfortunately Marisa and Reimu took it easy after getting back home with full stomach, so they forgot the location.
For the present, Marisa and Reimu is relieved from the duty. That Chen and Myon pair who eat soil accepted to give birth in exchange of the Soft Soft.
Patchouli then assess the number of each types from their group greeting and decided what children should be made to keep the number stable.
Unlike normal yukkuri, Cave Yukkuri herd doesn't put limitation on refreshing, instead it's encouraged. The preferred birth method is the mammalian birth. Unfortunately, the babies born from Cave Yukkuri are relatively big, those who has had babies before will never want to give birth anymore.
There's a case of scum Chen who killed her Reimu pair and eat her corpse. When she refused to make little ones, the herd punished her on spot and eat her corpse.
Cave Yukkuri usually live together in tight group except when hunting. Thanks to this, scum can be quickly recognized and killed.
Finally, the Abyuser faction's face seems more easy now after seeing scum and killing.
Next, the product presentation. Factory research worker has made many variation of the yukkuri. They have the same dough skin so it's easy to colour them to different colours. There's Reimu-colour Marisa, Marisa-colour Reimu, Mass Product Evangelion bald Reimu, and even Zaku Marisa equipped with LED light and fake eyes.
Because they don't have any sense of sight, they wont discriminate each others by appearance. In the transparent box is an impossible sight of modified yukkuri eating together silently.
Factory then named the Cave Yukkuri as White Minikkuri. They're popular among terrarium lovers. These are yukkuri lovers who kept their yukkuri in a simulated natural environment for observation.
Indeed, these yukkuri are perfect for lovers. They don't jump around; they can eat anything silently without making mess; they even eat up their own poo poo. Because of their sensitive hearing, the yukkuri don't like to make loud noise. More importantly, they can regulate their own population in regard to their food. When you want more White Minikkuri, just put more food into the terrarium. They also don't start killing each others just by different looks, so the owner can modify them to many designs.
Abyuse faction is not happy though. This is a Lover oriented product, not for them. The lack of eyes mean less parts to abyuse. Minikkuri are small and difficult to abyuse, but gathering group of this unmotivated-to-breed White Minikkuri is too bothersome.
There's research to create normal yukkuri with the same good quality, but it's still unsuccessful. Surely, if the research is completed, the Factory would be able to reap even more profit from the lovers.