How much money are you spending to go to Tokyo?
Whay would you waste any of your time there in a gym? Its one week, use the time as a break for your body.
I am in the gym 7days/week. Then, if something important gets in the way where I can't do my thing (travel etc)Ii forget about the weights for a few days and come back refreshed.
Or you could make it a unique experience that you could only get in Tokyo, go sprint in some rice fields.