But he declined to comment on speculation it would sell Apple's iPhone in Japan.
Softbank is trying to turn around its mobile phone unit, the smallest out of the three operators in Japan, that it bought for close to 2 trillion yen ($16.6 billion) from Britain's Vodafone Group last year.
Last week, shares of Softbank rose against a drop in the overall market on speculation it would be the most likely local partner for iPhone, a much anticipated wireless device equipped with the popular iPod digital music player.
Although Son, the billionaire founder of Softbank, declined to provide details on the possible iPhone launch, he said that Japan's wireless standard is different from the one adopted for the iPhone made by AT&T's Cingular Wireless in the United States.
A company source told Reuters earlier this week that Son, who is said to be a good friend of Apple CEO Steve Jobs, had attended theheld in San Francisco last week, where the U.S. consumer electronics maker .
Son made his comments to reporters in Tokyo after participating in a meeting with the telecoms ministry as a member of a business lobby group.
The chief executive also said Softbank plans to unveil the new handsets on January 25, more than a week after NTT DoCoMo and KDDI presented their latest line-up for the spring season, which includes the peak month of March, the end of the financial and academic year in Japan.
"We're preparing many models that are lots of fun," Son said without elaborating further.
Softbank would have to match the rival's new models unveiled on Tuesday, including DoCoMo's thinnest-ever high-speed handset, a phone featuring a touch-sensitive screen and a wide selection of digital TV devices from KDDI.