like minds gather; birds of a feather flock together
A classical idiomatic expression meaning people of similar character or interests naturally come together. Rare in modern conversation; mostly encountered in literary or formal contexts.
The phrase 同気相求む expresses that like-minded people naturally gather.
A more common modern proverb with a similar meaning, literally 'like calls to friend'.
From the 『易経』 phrase 同声相応、同気相求, “like sounds answer one another, and like energies seek one another.”