Annual profit at Japanese mobile carriersurged 65 percent, driven by strong demand for 's iPhone 4S.
Softbank, which did not break down quarterly numbers, Thursday reported a net profit of 313.8 billion yen ($3.9 billion) for the fiscal year through March, up from 189.7 billion yen the previous year.
Annual sales jumped nearly 7 percent to 3.2 trillion yen ($39.5 billion).
Tokyo-based Softbank credited the boost in earnings to iPhone 4S launched by in October.
The fortunes of Softbank, once the underdog in Japan's telecom industry, have improved after it started selling the iPhone in 2008.
Initially, Softbank was the only Japanese phone company to offer the iPhone. Rival KDDI Corp. began to sell the iPhone from late last year.
Softbank still remains the sole vendor of the popular iPad in Japan.
Softbank, which also offers fixed-line broadband services, has carried out an aggressive marketing drive in recent years, starring a talking white dog that has proved popular among Japanese.
Softbank's success defied initial skepticism about embracing Apple products because of the strong position of local electronics makers previously reputed for the world's most advanced cell phones.
Highlighting the success of that strategy was a key part of the earnings presentation by Softbank President Masayoshi Son, often praised as Japan's Steve Jobs.
"Softbank was the first to focus all our managerial resources on smartphones," Son said.
He said the three must-haves of the 20th Century — the washing machine, fridge and TV — had changed in the 21st century to the iPhone, iPad and cloud computing services.
Son has recently become highly visible in pushing solar technology. That has made him stand out even more because the government is eager to stick to nuclear power.
Japanese public interest in solar and other renewable energy has been growing since the March 11, 2011 tsunami set off a nuclear disaster in northeastern Japan.