Have you company offered to help you in anyway with your move?
i would imagine you would need company help with finding an apartment and a great many other settling-in issues, unless you speak Japanese. Housing is very, very expenisve and fairly difficult to find. Someone from you company will have to contact the appropriate offices to set up billing for your utilities, get you a phone, and get you settled in.
Where are you moving from? If you are coming from a country with relatively low living costs, you may find Tokyo expensive.
If you look at the
Tokyo section of the website you will find advice on things to do, transportation, weather, shopping etc. All useful information that could help when planning your trip.