With more Michelin-starred restaurants than any other city on earth, you shouldn't have a problem finding one that fits your needs. A few questions:
* How much are you willing to pay?
* Where are you staying? (I assume your boss isn't a native.)
* "Japanese-style" includes many things from homestyle food to hotpots, from sushi to curry and more. What's Japanese-style in your mind, or are you open to any type?
* How much lead time do you have to make a reservation?
* What kind of atmosphere are you looking for?