@Solistia
Hello, proofreading cat here.
I've checked with another TL and compared it to the original translation. It doesn't seem like a mistranslation on our part because if you were to check the raws for vol. 1 extra 6, I think it says years. Theoretically, I think the male employee is referring to Fukumaru's age in human years (10) which is around six months old. However, it would seem that Fukumaru refers to his age in cat years (1) which is 18 human years. In fact, I've also checked to see if it would fit in the timeline and it seems to fit in place if you take in consideration that a few years passed from page 3 to 4 and he still wouldn't be 1 years old in cat years. The only thing that strikes me as odd is that the female employee barely changes in appearance despite many years going by. If any of you have any good theories, feel free to tag me but, as of this moment, I don't think the 10 years is a mistranslation.