Nitori Kawashiro is a kappa who likes to live near water and can often be found in the Genbu Ravine or by the mountain streams that flow at the foot of the Youkai Mountain. She invents all kinds of items using kappa technology, including the optical camouflage suit she wears, and spends her days attempting to sell them. Today, she's on the Youkai Mountain to listen to a new business proposal.
Takane Yamashiro is a yamawaro, a type of kappa that lives in forests or on mountains. Her hideout is hidden high up on the Youkai Mountain, and while she's adept at using all sorts of technology, she excels as a businesswoman. Today, it seems she's called Nitori to discuss a product that used to be sold high up on the Youkai Mountain.
The specific differences between kappa and yamawaro are unknown, but fundamentally, they're very similar. Nitori and Takane are both rivals and business partners. By all accounts, Nitori handles technology and product design, while Takane takes care of raw material acquisition and sales. Nitori came to discuss business with Takane, but now she had a look of suspicion on her face.
"Hey, Nitori, do you know what these are? They're called Ability Cards," said Takane. That's right. Takane had a business proposal of her own, and it involved technology Nitori knew nothing about.
Ability Cards are cards that contain various abilities and were once the subject of an incident-related investigation. One of the Great Tengu created them from divine materials, joined forces with the god of markets, and began selling them. At that time, Takane also began selling them as part of a new business venture.
The question is, are the cards she's presenting to Nitori ones she had left over from before, or are they a new invention designed in their image?
"...I see. That's pretty clever," said Nitori.
"You catch on fast. Can you make them for me?" replied Takane.
"Who do you think you're talking to? I'm the best engineer in all of Gensokyo!"
Apparently, the items Takane wanted Nitori to mass produce weren't Ability Cards but an invention inspired by them. And with that, Takane's business proposal was a success. Or so she thought... A short while later, she was almost eviscerated by the Hakurei shrine maiden, who suspected the return of the Ability Card Incident. But that's a story for another time.