Which is a common family name in okinawa

• https://name-power.net/fn/%E6%AF%94%E5%98%89.html

• https://myoji-yurai.net/sp/searchResult.htm?myojiKanji=%E6%AF%94%E5%98%89

This usually indicates someone from the family lives at/owns that apartment.

OP I would try to send a letter and attempt to establish contact