Maruzen Marunouchi Children's Books

Dozens of character shops in the basement under the station, from Pokémon, Kirby and Ultraman to Tomica and Plarail, Lego and the TV networks' own stores.

Tiny cars everywhere, plus store exclusives for a vehicle-obsessed child.

Tomica cars and Plarail trains that pop out on a 3D screen, digital mini games, and a super-size Plarail diorama out front.

Minerals, fossils, animal specimens and century-old university furniture from the University of Tokyo's collections, plus a small chamber of curiosities.

Japanese-style rooms, and connecting rooms for up to six with two bathrooms and an inner door you can close at night, a five-minute walk from the station.

Free, with Japan's money shown in order through its history and a corner where you feel how heavy 100 million yen in bills is.