Going from Japanese to Faroese (Føroyskt) has a composite linguistic distance of 90% (heuristic estimate). Below is the dimension-by-dimension breakdown.
Shared vocabulary, cognates, and loanwords.
Morphology, syntax, word order, cases.
Shared sounds and phoneme inventory.
Japanese → Latin
Japonic ↔ Indo-European
The 5 languages with the lowest linguistic distance from Japanese:
A quick 3-question check between Japanese and Faroese. No signup.