The Cabinet Office of Japan releases 2013 status report with details on mobile youth usage behaviors http://bit.ly/PA5hh9
Machine Translation [.pdf]
The “Internet environment survey of Youth” study period was 9th November to 8th December 2013. Intended for ages 10 to 17 years old, interview format was carried out. The total individuals recovery rate is: 1,993 guardians and 1,817 youths.
Growing smartphone use ratio is particularly noticeable in high school, reached to 82.8%. In contrast, junior high school students 47.4% and 13.6% in elementary school. Of the youth who own mobile phones and smart phones, are you using the Internet at the same terminal 44.3% in elementary school, 82.1% in middle school students, 96.7% in high school students.
For the purpose of use, while still show a downward trend for “mail” compared to the previous year, “SNS sites”, “communication such as chat”, “game” (and videos and other music), grew substantially in each age. It was a tendency that Internet usage time extending as a whole, average daily usage time for smartphone’s total was 107.4 minutes.