In central Tokyo, hundreds lined the streets.
Softbank, the country's exclusive seller of the iPhone until today, held a ceremony at its main retail store in the upscale Harajuku district.
The death of Steve Jobs last week was still heavy on people's minds. At the Apple store in the hip Shibuya district, fresh flowers were laid in memorial.
But there was still a festive atmosphere as fans flocked in their hundreds to get their hands on the new iPhone 4S.
The lines stretched for several blocks, and as the temperature rose employees passed out drinks and Apple umbrellas. Customers at several shops said booking systems had frozen and disrupted some sales.
But the lines weren't quite as long as for past launches, in part because companies like Softbank now carry dozens of smartphone challengers.
Also, for the first time two Japanese carriers will carry the iPhone.
Softbank was once a distant third to rival au, but has steadily gained on its rival. Au now has its first iphone, and has launched aggressive pricing to lure customers.
Lines appeared longer at Softbank stores, but many feel that au's stronger network will give it an advantage.