That was Kanae's younger sister, unable to fight off her drowsiness any longer, lying on the floor asleep.
Come to think of it, Tamayo's true contact with the Demon Slayer Corps—her contact with Kanae—had only officially begun then.
Before four years ago, the Demon Slayer Corps had known nothing of her whereabouts. During one of her trips to gather herbs, she had happened to encounter Kanae and had nearly had her identity exposed.
Although Kanae had not discovered it at the time, Master Ubuyashiki noticed afterward and secretly proposed an alliance to her.
Master Ubuyashiki probably knew of her existence because she had worked and kept in contact with a Demon Slayer Corps member several centuries ago, leaving behind some sort of information through that person.
His gaze shifted to another child around twelve years old. This was an Oni who could be called the perfect form that Muzan Kibutsuji sought. By now, the child had long since fallen asleep beside Shinobu.
Only then did Tamayo realize how late it had become.
When she had first begun eagerly seeking knowledge, it had not even been noon. She had kept asking without stopping, and neither lunch nor dinner had been served.
Her assistant Yushiro had also gone out into the mountains to gather herbs. Otherwise, he could have helped entertain them.
Yushiro was an Oni as well, but he had not become one by receiving Muzan Kibutsuji's blood.
Yushiro had become an Oni through Tamayo's methods.
At the time, Yushiro had been gravely ill, and ordinary treatment had been useless. Tamayo could not bear to watch the child die. Seeing the shadow of her own child in him, she had turned him into an Oni.
"I'm terribly sorry for taking up so much of your time~"
Tamayo spoke with deep apology