Foreigners are housed all together in Japan's prison system, and it is brutal, they don't play around. 3 years in there is not an easy stretch, not even a little bit.
The legal system in Japan is not the same as the West, you don't have a lot of the rights there that you would have in the West. Furthermore, criminality is treated very harshly there due to the historically conformist culture.
Foreigners are housed all together in Japan's prison system, and it is brutal, they don't play around. 3 years in there is not an easy stretch, not even a little bit.
The legal system in Japan is not the same as the West, you don't have a lot of the rights there that you would have in the West. Furthermore, criminality is treated very harshly there due to the historically conformist culture.
Also: they have a very high conviction rate. I doubt he could wiggle himself out since it was on camera.