noun
happily married couple; lovebirds
Literary expression originating from Chinese mythology, referring to a pair of birds with one wing each that must fly together, symbolizing an inseparable married couple.
あの二人はまさに比翼の鳥のような夫婦だ。
Those two are truly a couple like the legendary birds that share a wing.
おしどり夫婦 is a more common, everyday expression for a devoted married couple, while 比翼の鳥 is a more literary and classical metaphor.
From Chinese mythology, where a pair of birds each have only one wing and must fly together, symbolizing an inseparable union. The exact historical derivation is uncertain, but the expression is conventionally associated with marital harmony.