https://brew.sh/ Here, when switching to Japanese, a bug that homebrew search does not work at all. If you use English, you can use homebrew search.
So, if you search for sass
sass/sass/sass
Will come out
brew install sass/sass/sass
I was able to install with
If it doesn't work, the ruby version is too new, so it's a good idea to revert to the version.
rbenv install 2.5.0