For a while, in exchange for an increase in oil imports, the Japanese dropped all visa restrictions.
I probably never would have been aware that so many of the Middle Eastern looking people in Roppongi were Iranians (I can spot the other largest group, Turks, as I still speak enough Turkish from when I lived there to at least spot when it is being spoken) if a friend of my wife wasn’t married to an Iranian guy. Now that I’ve looked into it, though, I’ve found a couple of great links that I think would be of interest to anyone:
A short story about Iranians in Japan from The Iranian
Wikipedia on Iranians in Japan (surprisingly detailed for such a seemingly obscure subject)
For Japanese people, now that the fake phone card dealers are long gone from the parks the only famous connection to Iran is Yu Darvish, the half-Iranian baseball player who is apparently good at this “sport” and apparently good looking. Can’t make a judgement on either count I’m afraid, you can judge for yourself here. What I can now tell you is that he probably shouldn’t be in this post at all as his parents met in the states, making his father far from a typical Iranian in Japan.