The author mentions time stopping once a year, but doesn't do anything special around this particular fact. I kept waiting for something unexplainable.
Right? I thought the time would stop the moment they both come and stay like this frozen in time, but nothing happened. After the end of the story I guessed that the sentence was a translation error and just meant that the clocks would stop and they had to start them again...
A simple thing like a bell can mean so much to some people, yeah?
Also I find it interesting that they didn't even bother to explain why she has fox ears and the tail...Don't need to, they're just great.