Underneath the ferris wheel of the amusement park.
Kamiya did indeed ask Mimiko about the situation, mainly about her defeating the Kawazaru.
With the Little River Turtle's simple nature, she had no idea how to keep things secret, so she just blurted out everything she knew.
Including how she became enemies with the Kawazaru.
Including how she hid in the Kuzuryū River, waiting for the opportunity to kill the Kawazaru.
Even including what she obtained after defeating the Kawazaru.
Every detail, she divulged completely.
And upon learning these details, Kamiya began to enthusiastically examine Mimiko's body...
Kamiyagawa: "Turn around again, Mimiko."
Mimiko: "Like this?"
"Yes, just like that, and hold still, don't move."
"Hmm... It's a little, a little ticklish, Lord Kamiya."
He tapped on the sturdy turtle shell and squeezed Mimiko's soft and elastic arms as she completely relaxed.