"Moshuiii!"
Kir's aggravated cry came from having thought he was pouring himself a pre-made carafe of coffee, only to discover something more like vaguely coffee-scented hot squidshark oil.
Kiryu had been tickled to discover that Ayther had no natural oil deposits. The moment Kir had tried to propose drilling, he'd run into the consensus that oil was a thing that living beings make. That wasn't necessarily preclusive, but he had yet to even verify if there was a fossil record, much less crude oil. And until then, he would need to piece together the most efficient ways to get vegetable oils if he was going to expand the steel mill.
Regardless, there was no good reason for any kind of oil to be in his coffee pot.
Opening the door to the basement, he found his "protege" slathering refined oil onto the cutting edges of the five-axis mill Kir had developed with her - a significant upgrade from the arcane mill he'd turned into Goro.