If you've got yourself some spare time whilst in Tokyo, why not escape to some Yokohama. Here you could visit the iconic Rainbow wheel, a huge shopping mall and a waterfront park. 'Escaping' from Tokyo, you will be delighted by the (marginal) increase in space and sense of openness as a breeze blows over the water. Get a train from numerous stations across Tokyo, including key stations such as Shinjuku.
www.welcome.city.yokohama.jp/eng/tourism/