noun
someone else's business; matter of no concern
Refers to something that is not one's own affair; often used to dismiss or distance oneself from a matter.
彼の失敗は私にとってよそ事だ。
His failure is none of my business.
よそ事のように聞こえるかもしれないが、実は関係がある。
It may sound like someone else's problem, but it actually concerns you.
Compound of よそ (another place, outside) and 事 (matter, affair). The exact historical derivation is uncertain, but the word has been used since classical Japanese to mean 'something unrelated to oneself'.