Japanese also like mobile phone. I think iPhone had changed our life. Japanese are not good at computer. To write Japanese character by English keyboard is need to the knack a little. Many Japanese are meet with a setback about it and felt that not good at computer. So internet is not popular till 10 years ago for Japanese.
About 20years ago mobile phone has appeared. It can only talk. At first this phone was very big and can talk in a limited area. The technology has advanced and the phone has become small and talk well everywhere. But it means only talk not can internet everywhere.
On the next stage we can sent some characters to use mobile phone. Japanese language has many characters for ex Hiragana Katakana Kanji etc. We can use very limited character in this time. We can sent very short message. This situation could not see internet webpage. This mobile phone data traffic was limited. The last version that now sold were can see internet web page and can enjoy YouTube movie but when data is so big it cannot see. The feature this phone is two folded and enter character in button. I and my wife use this one even now. This type phone was called in Japanese slang Garakei and this one share was 50% till last year. I think this Garakei not be eliminated in Japanese market. This is very good for old Japanese.
The smart phone had appeared and everyone replacement purchases. Everyone can enjoy webpage and YouTube and many communication services about LINE. This situation had changed our life especially the younger generation. As you know there are many game maker in Japanese and they had released a lot of games. At first they are FREE but to go next good stage it needs some charges. And LINE can communicate not to talk only character. This situation become a problem in Japan.
In Japan when buying a smart phone we must make the contact of telephone line together. When you buy iPhone touch you must make the contact of Wi-Fi together. The situation of Japanese Wi-Fi is very bad. There are many area to use Wi-Fi, but it needs to registration of e-mail address. The perfect FREE Wi-Fi is little nothing. I had contracted mobile router of Wi-Fi, it needs $40 /monthly costs. Japanese government said that to improve towards the TOKYO Olympic Games in 2020.