[x] Try to make some idle talk.
You think you see where this is heading, but... well, beating the kappa into submission just doesn't seem practical. Maybe it's better to try and get on their good side. And she does seem to like talking about herself.
"What, you mean like little cameras in the bushes or something?" you wonder. You're curious about these, too. "How does that even work?"
Nitori looks at you blankly. "What do you mean?"
"I mean," You continue, "They need to be powered, right? And you've got to have some kind of way to get the images back to... wherever you're watching them."
"Oh," Sanae says, loosening her tension a bit, "I guess they can't just stick them on the cell network, can they?"
The kappa nods, sagely. "That's right. That's why it's so cool, because I had to figure out all that stuff. But what's a 'cell network'?"
Sanae scratches her head. "Well, it's kind of a... I dunno, it's really complicated to explain. But our cell phones connect to it."
As if remembering something, Sanae pulls a flip phone from her pocket. It's covered in brightly colored little frogs and snakes, and there's a frog-shaped charm hanging from it, but you think you recognize the model. She opens it.
"No service," She says, turning to you, "Imagine that! I guess I can't call someone."
Sanae turns back to the kappa, who's now staring intently at the phone. She turns it around. "You see, we can talk to---"
"Wait, there's a remote network it has to connect to?" Nitori blurts out. In a whirl of motion, she flings her pack off her back and starts digging around in it. "Everything inside was so small, I didn't see a radio... aha!"
With pride, she draws her own phone out of the pack. It's almost as decorated as Sanae's, though it's covered in different little animals like foxes. It's quite a bit more nicked up than Sanae's, too. "I have one too! So, can we make them talk directly?"
Sanae laughs, clearly not expecting this. "N-no, I don't think so."
"So," The kappa presses, "How do I make the screen glow like on yours?"
"Is the battery dead?" You wonder, "I'm not sure how you got that thing, but I imagine it didn't come with a charger."
You can tell that Nitori can barely contain herself. "I didn't see a battery. Say, do you two want to come back to my lab? We can talk more there!"
Sanae looks to you. "Hmm. What do you think?"
[ ] You can't really refuse.
[ ] Suggest she come up to the shrine, instead.