Japanese consumers cannot get enough of cup ramen, with spending on them surging by more than a quarter over the past year. That sounds like good news, but for a country still struggling to escape deflation it is a worrying signal.

Weak consumer spending is fueling speculation that Prime Minister Shinzo Abe will again delay a planned sales tax hike, and Japan is expected to have dodged a recession at the start of this year by the smallest of margins — helped by an extra "leap year" day in the January-March quarter.

Consumption, one of the few economic engines that fired when Abe launched his Abenomics stimulus plan more than three years ago, is faltering. And rising sales of cheap cup noodles is a worrying sign that consumers have little confidence that deflation is being banished.