大山鳴動して鼠一匹
Meanings
1
much ado about nothing; great cry and little wool; the mountain labored and brought forth a mouse
Proverb meaning a big fuss leads to a trivial result. Often used when expectations are high but the outcome is disappointing.
After all the fuss, it turned out to be much ado about nothing.
The new product announcement ended up being a great cry and little wool.