Ok, Mas is awesome. He was extremely helpful and flexible throughout our stay.
Mas' apartment is even better! Very nicely designed with high end furnishings and nice touches like great soaps and coffee. The apartment is also in a very convenient location -- close to the Yurakucho JR station and Hibiya subway station. The palace is a short walk and there are several large parks just around the corner. The street is great, as well, with several smoky yakitori and a great ramen joint next door.
Mas' apartment was perfect for exploring all over Tokyo but always feeling like we had an oasis to retire to.