Japan's longest run of economic expansion since the 1980s asset bubble may be entering a turning point, with data out on Friday suggesting consumption will fail to drive growth if trade frictions undermine exports.

Household spending shrank 0.9 percent in February from a year earlier — the biggest drop since a 1.4 percent fall in April last year — while inflation-adjusted real wages fell for a third straight month in February, undercutting consumer buying power.

A slowdown in consumption would be an additional headache for policymakers, who fret that the yen's recent rises and fears of a trade war could hurt the export-reliant economy.