Koyuki was reading it here: https://dynasty-scans.com/chapters/nettaigyo_wa_yuki_ni_kogareru_ch14#13 while writing her own fix fic of the ending that ended up happening to her in real life.
In practice, it was not the salamander but his companion in the hollow of the rock who was first careless enough to heave a deep sigh. "Aaaah..." went the sigh, like the faintest of breezes. It was the sight of the hair moss busily scattering its pollen, as it had done the year before, that had inspired it.
The salamander could hardly fail to hear. He looked upwards, and with eyes full of friendship inquired:
"You just heaved a big sigh just now, didn't you?"
"And what if I did?" responded the other defensively.
"Don't reply like that. You can come down from there now."
"I'm too starved to move."
"You mean, you think you've had it?"
"I think I've had it."
It was some time before the salamander inquired again:
"What would you say you're thinking of now?"
"Even now," replied the frog with the utmost diffidence, "I'm not really annoyed with you."
Textbook tsundere reply.
By the way, I feel like with the author's love of callbacks, Koyuki will eventually end up saying that line: "I wish we could always be together." once the time for her to actually leave approaches. The end of the chapter I linked even has it in the editorial blurb. "... So, then what about you, Konatsu-chan? Do you want us to always be together? For me, I'm sure that I..." She won't ask her, she can't ask her, at least for now...
last edited at Jul 28, 2020 4:00PM