Seiji's apartment, the Marble Mansion is fabulous for staying in the Shinjuku area. The subway is a quick walk, and the apartment is very easy to find. Seiji's instructions were very easy to follow. The apartment is very spacious and includes all amenities required for your stay. Convenience stores, restaurants and bars are all within walking distance. The apartment itself is located in a quiet street though so not much noise. I would recommend Seiji's apartment to individuals, couples and families. A wonderful experience in Tokyo :)