accidental resemblance
Refers to a coincidental likeness between unrelated people or things. Often used in the set phrase 他人の空似 (たにんのそらに), meaning a chance resemblance between strangers.
See also: 他人の空似
Those two aren't related, but they look exactly alike. It's truly a case of accidental resemblance.
The person in this photo looks like me, but it's probably just a coincidence.
false friend
Standard kanji spelling.
Mixed kana-kanji spelling, also used.
Compound of 空 (そら, 'empty, false') and 似 (に, 'resemblance'). The exact historical derivation is uncertain, but the word has been used since at least the Edo period to describe chance likeness.