Note that kokoro (心) means “heart” in the sense of “spirit,” “soul,” “mind,” “emotions,” etc. It doesn’t mean “heart” in the sense of “internal organ that pumps blood.” That is shinzō (心臓).

I once heard an American friend with so-so Japanese ability ask a Japanese woman who had recently had a heart operation how her kokoro was doing, and she looked surprised and taken aback.

Side note: After I started reading HN in 2019, I was struck by how many tech products mentioned here have Japanese names. I compiled a list for a few years and eventually posted it:

https://news.ycombinator.com/item?id=31310370

Its also the name of the AI in Terminator Zero https://villains.fandom.com/wiki/Kokoro

I'm not sure if that is related here.