Here is some info about about not using FRS/GMRS radios in Japan:
http://www.tele.soumu.go.jp/e/monitoring_qa/foreign.htm
Frequencies in the range from 440MHz-470MHz are used in Japan for the following:
i) Cargo/passenger transportation service including taxi, railway and bus radios
Anti-Disaster Emergency Radio Telephones by NTT East and West
Aural program transmission by broadcasters
ii) Unlicensed low-power stations such as radiophones, data transmission equipment and
medical telemeters
Copied from
http://www.tele.soumu.go.jp/e/search...e0303/335m.pdf