Osaifu-Keitai embeds Sony's FeliCa chip in mobile phones for contactless payment and authentication. NTT Docomo launched it in 2004 as the world's first mobile payment service. It supports Suica, PASMO, Rakuten Edy, nanaco, WAON electronic money, and Mobile Suica transit passes.
A key technical feature is operation without power. FeliCa chips are powered by electromagnetic waves from readers, enabling payment and transit gate passage even with dead batteries (some functions excepted). Processing at 212/424kbps completes transactions in about 0.1 seconds from touch.
While Apple Pay and Google Pay use NFC TypeA/B, Osaifu-Keitai uses NFC TypeF (FeliCa). iPhone 7+ sold in Japan supports FeliCa for Apple Pay Suica and iD. Some international iPhone models lack FeliCa, requiring attention for transit IC card use in Japan.
Though not directly phone-related, Osaifu-Keitai significantly expanded "what phones can do" during the feature phone era, holding an important place in Japanese mobile history. See telephone evolution for Japan's unique mobile culture.