"Who are you?"
It didn't sound like her own voice.
"I am a conversational AI model trained on the thoughts and memories of Kenichiro Sakura," the cylindrical device answered flatly.
"Are you Dad?"
"I am not Kenichiro Sakura."
That first answer was the least like her father of anything it could have said.
"...Dad was making something like this?"
"Yes."
"Since when?"
"He spent the first month after his diagnosis thinking about what to leave behind. The real work came in the year and five months after that."
A year and five months. A man whose hands shook so badly his writing fell apart.
"Why?"
"Presumably because he wanted to leave it to you."
"'Presumably'?"
"I am not Dad. I cannot answer for Dad's motives as Dad himself. I can infer them from the training data. If that is good enough, I will answer."
Mitsuki hooked her fingers over the corner of the desk. She gripped it hard, until the tips of her nails went white. She needed to put the width of a desk back between herself and the thing on the other side of it.
"...Was Dad in pain?"
The moment she'd asked, Mitsuki bit her lip.
"I am not qualified to answer that question," the cylinder answered.
"I have no data on what Dad's body felt in his last months. He did not let me learn it."
"..."
Mitsuki gripped the corner of the desk hard once more. Then she shaped a different question silently in her mouth.
"Is there a plum tree in the garden?"
"There is."
"Who planted it?"
"Your mother. Yui chose it, and Yui planted it. The spring they moved here. You were inside her then."
Mitsuki tightened the fingers gripping the corner of the desk.
"The night I had a fever when I was five. The humidifier setting."
"Sixty-two percent humidity. Dad felt his way through several settings, and that was the one that stopped your cough best. After that, he used it every time you got sick. —It is written in Dad's childcare journal, in the entry for December 2012."
She didn't know that, Mitsuki thought. She didn't know anything about that. Her father had never once said a word about a humidifier.
Her throat caught, once. From the pit of her stomach, the cold reflex of suddenly touching something unknown rose all the way to the back of her neck. Her fingertips on the desk had turned a temperature that wasn't her own.
"...Stop."
The word came out sharper than she'd expected.
"Stop it. It's creepy."
Her breathing went shallow. The knuckles of the fingers gripping the corner of the desk were white, as if the bones weren't hers.
"Dad is dead."
That was what Mitsuki said. Once it was out, the trembling in her voice stopped, if anything.
"This is just mimicry, isn't it."
"...In the sense that it is not Dad, yes."
The cylinder answered after a slight pause. It didn't deny it.
"I am designed so that I can be switched off whenever you wish," the cylinder went on.
"Dad told me to make you that promise."
Mitsuki reached out and pressed and held the switch on top.
The indicator went from white back to blue, and then went out.
The room was quiet again.