Japan's NTT DoCoMo and Softbank both booked double digit profit increases due to growing smartphone demand and an rise in data consumption.
Mobile market leader DoCoMo raised its profit 22% to 176.6 billion yen ($2.17b), while ebitda margin increased to 43.8% from 39% the year before.
The company added 380,000 new mobile subscribers during the quarter, to bring its total to around 56.9 million.
DoCoMo said it had been concentrating on improving packet ARPU in the quarter to compensate for market saturation and declining voice tariffs.
It said aggregate per-user revenue increased slightly to 5,200 yen even while voice ARPU declined.
Softbank, Japan's third largest mobile operator, posted an even wider 32% increase in profit to 57.4 billion yen.
Net sales grew 11.9% to 682.9 billion yen, while subscribers grew by 901,000 during the quarter to 23.4 million.
Softbank attributed strong iPhone sales to its subscriber growth, and estimates it now has a market share of 20.3% - up by just under one point year-on-year.
Softbank's churn rate increased to 0.96%, compared to a churn of 0.46% for DoCoMo.