local mistress; local wife
Refers to a local woman who is treated as a wife by a foreign man already married elsewhere, often in the context of long-term business postings or expatriate life. The term carries a somewhat negative or informal connotation.
He took a local mistress during his overseas assignment.
He has a child with his local wife.
Compound of 現地 (genchi, 'local') and 妻 (tsuma, 'wife'). The term likely arose in the context of Japanese businessmen posted abroad who maintained a local partner.