Having moved to Tokyo in 2007, I have spent a lot of time familiarising myself with the city and in the process have eaten at many restaurants. Many good, some bad: my thoughts on what I have found are found here. I hope you find time to test a few of my recommendations.
Incidentally, if ever you find yourself in Iceland, please visit my friend's website www.gastroshark.com for all the best places to eat there. Difference is, Chris actually knows what he's talking about.