The staff ate it later

It's related to the concept of Mottainai (もったいない, 勿体無い) in Japanese culture. Where any waste is considered bad, specially related to food.

https://en.wikipedia.org/wiki/Mottainai

This is similar to the Japanese concept of Shitsurei (失礼, しつれい). It is of course impossible to comprehend this unique idea that no other world culture has ever conceived of. What a remarkable society!

I did chuckle a bit, but the idea of mottainai is just way more prevalent within Japan, compared to Western countries. I can't speak for other Asian countries, but it's very easy to feel that compared to North America and Europe (places that I've lived in). Funnily, I've felt it in post-soviet countries as well, but that's coming from the feeling of scarcity in the beforetimes.

I’ve also lived in NA Europe and Japan and disagree with this sentiment.

“Don’t waste stuff” is taught by plenty of parents, people talk about using every bit of the buffalo in America. Everyone in my generation has the grandparent who threw nothing away.

There’s maybe more modern examples of cultural thrift in Japan due to the postwar experience compared to the US… but even then.

I feel like I’m talking to aliens when these discussions of “unique Japan” things come up that are, in my experience, plenty present abroad.

I don’t even think Japan is particularly that good about reuse and waste beyond its recycling programs!

Maybe I'm wrong, but from my personal experiences in NA and Europe, even though wasting is "frowned upon", there's no feeling of "guilt" with the action of "waste". Honestly, I'm not sure how to explain it.