"Speaking of which, I haven't yet asked for your names."
"Why so formal all of a sudden..."
"What's the big deal? I am a Showa-era girl who believes in repaying kindness! Is it weird to want to know the names of the people who helped me?!"
"Kagura Hikaru."
"Komori Ai!"
"I am Mizuno Yuna, an unworthy young woman, please take good care of me."
The above conversation happened while the three were descending the mountain.
They were on their way to the killer's house.
First premise, this rural town is very small, with a population of less than a thousand, and the neighbors know each other well.
Second premise, as the deceased Shrine Maiden Mizuno Yuna had seen the killer's face and knew who he was.
Answer: There was no need for deduction, they just had to go directly to the killer's house to arrest him, this novel didn't even have a detective's role!
Kagura Hikaru had already made a contingency plan.
