Although the schedule was too tight to apply for a Japanese foreign amateur radio license (see http://www.jarl.or.jp/English/3_Application/A-3.htm for details) I carried my scanner with me and did some listening anyway. I monitored activity on the following frequencies:
| Frequency | Remarks |
|---|---|
| 2 m | |
| 144.0200 MHz | |
| 144.1600 MHz | |
| 144.6200 MHz | |
| 144.6400 MHz | 1200 Baud APRS |
| 144.6600 MHz | |
| 144.7200 MHz | |
| 144.7600 MHz | |
| 145.0400 MHz | |
| 145.1000 MHz | |
| 145.1400 MHz | |
| 145.1800 MHz | |
| 145.3800 MHz | |
| 145.4600 MHz | |
| 145.6200 MHz | |
| 145.7500 MHz | |
| 70 cm | |
| 430.0600 MHz | |
| 430.0800 MHz | |
| 430.1000 MHz | |
| 430.2200 MHz | |
| 430.2400 MHz | |
| 430.3000 MHz | |
| 430.3400 MHz | |
| 430.4600 MHz | |
| 430.6000 MHz | |
| 430.6200 MHz | |
| 430.6400 MHz | |
| 430.6600 MHz | |
| 430.6800 MHz | |
| 430.7000 MHz | |
| 430.7800 MHz | |
| 430.8200 MHz | |
| 430.9800 MHz | |
| 431.1000 MHz | |
| 431.2600 MHz | |
| 431.3000 MHz | |
| 431.3600 MHz | |
| 431.4200 MHz | |
| 431.6000 MHz | |
| 431.6200 MHz | |
| 431.6800 MHz | |
| 431.7200 MHz | |
| 431.9600 MHz | |
| 432.0800 MHz | |
| 432.1000 MHz | |
| 432.2000 MHz | |
| 432.2600 MHz | |
| 432.2800 MHz | |
| 432.3000 MHz | |
| 432.4000 MHz | |
| 432.4400 MHz | |
| 432.5000 MHz | |
| 432.6600 MHz | |
| 432.6800 MHz | |
| 432.7400 MHz | |
| 432.7800 MHz | |
| 432.8600 MHz | |
| 432.9000 MHz | |
| 432.9400 MHz | |
| 432.9800 MHz | |
| 433.0000 MHz | |
| 433.1000 MHz | |
| 433.1200 MHz | |
| 433.1400 MHz | |
| 433.1600 MHz | |
| 433.1800 MHz | |
| 433.2000 MHz | |
| 433.4400 MHz | |
| 433.4800 MHz | |
| 433.5800 MHz | |
| 433.6000 MHz | |
| 433.7000 MHz | |
| 433.7200 MHz | |
| 433.7400 MHz | |
| 433.9600 MHz | |
| 434.1200 MHz | |
| 434.4000 MHz | digital (sounded like 1200 Baud APRS) |
| 434.4800 MHz | |
| 434.5400 MHz | |
| 434.6200 MHz | |
| 434.7400 MHz | |
| 434.8200 MHz | |
| 434.8400 MHz | |
| 434.9600 MHz | |
| 435.0400 MHz | |
| 435.1000 MHz | |
| 435.3000 MHz | |
| 435.3600 MHz | |
| 435.4000 MHz | |
| 435.5200 MHz | |
| 435.5500 MHz | |
| 435.6000 MHz | |
| 435.6200 MHz | |
| 435.7200 MHz | |
| 435.7400 MHz | |
| 435.7600 MHz | |
| 435.8200 MHz | |
| 436.0200 MHz | |
| 436.1200 MHz | |
| 436.2400 MHz | |
| 436.2600 MHz | |
| 436.3000 MHz | |
| 436.3800 MHz | |
| 436.6200 MHz | |
| 436.6400 MHz | |
| 436.7000 MHz | |
| 436.8000 MHz | |
| 436.8200 MHz | |
| 436.8800 MHz | |
| 436.9200 MHz | |
| 436.9600 MHz | |
| 436.9800 MHz | |
| 437.0400 MHz | |
| 437.1400 MHz | |
| 437.2200 MHz | |
| 437.3600 MHz | |
| 437.3800 MHz | |
| 437.5000 MHz | |
| 437.5800 MHz | |
| 437.6400 MHz | |
| 437.7400 MHz | |
| 437.8200 MHz | |
| 437.9000 MHz | |
| 437.9200 MHz | |
| 438.0000 MHz | |
| 438.0200 MHz | |
| 438.0400 MHz | |
| 438.1400 MHz | |
| 438.1600 MHz | |
| 438.2000 MHz | |
| 438.2200 MHz | |
| 438.2600 MHz | |
| 438.2800 MHz | |
| 438.3600 MHz | |
| 438.3800 MHz | |
| 438.4600 MHz | |
| 438.5000 MHz | |
| 438.5800 MHz | |
| 438.6200 MHz | |
| 438.7800 MHz | |
| 438.8000 MHz | |
| 438.8400 MHz | |
| 438.8800 MHz | |
| 438.9000 MHz | |
| 439.0800 MHz | |
| 439.1200 MHz | |
| 439.4400 MHz | repeater |
| 439.5400 MHz | |
| 439.6000 MHz | |
| 439.7400 MHz | repeater |
| 439.8000 MHz | |
| 439.8600 MHz | repeater |
| 439.9000 MHz | |
| 439.9600 MHz | |
| 439.9700 MHz | repeater |
| 23 cm | |
| 1288.9500 MHz | |
| 1291.2200 MHz | |
| 1299.9900 MHz | digital (D-STAR?) |
Compared to Germany there is a LOT more activity on the VHF/UHF bands, as you can see above. Especially 70 cm is very crowded. Callsigns were rarely used (and are hard to understand :-). Surprisingly I found no Packet Radio traffic despite APRS.
The Japanese bandplan can be found here: http://www.jarl.or.jp/English/6_Band_Plan/JapaneseAmateurBandplans20090330.pdf
I also used the time to have a look around in Akihabara, the well known "Electric Town" of Tokyo. You will find a huge number of anime, electronics, computer, camera, and other electronic shops there. The area seems just like a very huge electronics mall. Also of course there you will find a big Yodobashi store.
Here are some pictures of Akihabara and some radio shops I've found: