The tuna auction at Tokyo's Tsukiji fish market begins at 5.30am every day, and the queue to be one of 120 tourists permitted to witness it grows well before dawn. One of the best ways to scratch the surface of Japanese life is to consume – to shop, to eat – and Tsukiji is a perfect place to start. But you have to start early. By 6am, the tuna have been sold and are on the slab, where they're sliced and diced into steaks. At Tsukiji's first auction this year, an endangered bluefin sold for an impressive, if ethically dubious, £438,000. Avoid being run down by the zig-zagging electric tare carts, and you'll find an encyclopaedic selection of seafood in the maze of stalls here. By dusk each day, £5m of fish will have changed hands.
Tsukiji's traders are indomitable envoys for food, commerce and tradition, yet even this market closed briefly in 2011, when much of Japan was devastated by the earthquake and tsunami that struck exactly a year ago. Though the traders went back to work within the week, tourists were banned from the tuna auction for more than four months.
Still, Tokyo is as big and as resilient as London or New York, and, 12 months on, the city's scars are only apparent if you persuade a reticent local to discuss them.
In fact, with a world-topping metropolitan population of more than 36 million, it's so big that any enlightening walk will include some interstitial subway rides. So prepare yourself with a sushi breakfast at Ryu Sushi (00 81 335 476 894), one of the market's row of early-opening sushi joints, then stroll towards Shimbashi station.
Public transport in Tokyo is much easier for British people to negotiate than is the Tube for Japanese visitors to London. The extensive and efficient metro is complemented by the overground Yamanote Line, which appears as a green loop on the Tokyo metro map, and connects most of the city's places of interest on its circular route. Get yourself a Pasmo stored-value travelcard (pasmo.co.jp/en).
From Shimbashi, it's four stops north on the Yamanote Line to Akihabara, and "Electric Town", where the streets are deep with otaku ("geeks"). In the basements of multi-storey gaming arcades such as the Taito tower, grown men chain-smoke and watch each other play Tekken and Super Street Fighter IV. One floor up, teenagers boogie furiously on Dance Dance Revolution pads, among rows and rows of end-of-the-pier claw-grabber games. In the Tora No Ana bookstore (www. toranoana.jp), next-door to Taito, the shelves of manga are divided by age and gender, and men crowd into their allotted aisles to stand and read comics. This is also the district for cheap electronics and designer toys.
French cuisine is one of Japan's favourite imports; French-style bistros and bakeries abound. One odd side-effect of this, however, is the "maid café". Young women dressed as French maids cluster on street corners in Akihabara, advertising their services; no, not those kind of services. A short walk north up Chuo Dori from Tora No Ana and a left-turn into the side streets brings you to the T&K Akiba Building, address of the Pinky Café (00 81 3 3254 6777; www.pinkycafe.com). Customers pay almost £40 per hour to sit in a pink room decorated with Hello Kitty dolls, where – for a price – waitresses will squeeze chocolate sauce on to your pudding in the shape of a kitten, play a children's game, or squeak excitedly as they squelch your burger bap.
From Akihabara, hop back on to the Yamanote line. A leisurely ride through the northern districts will bring you finally to Harajuku, on the west side of the city centre. If you failed to brave a maid café, you'll be hungry again by now, so stop in at Jangara (kyusyujangara.co.jp), just a few steps from Harajuku subway station on Omotesando, for a bowl of tonkotsu ("pig bone") ramen.
If it's eclectic Japanese fashions you're after, walk down Omotesando past the Nike store to the junction with Meiji Dori and take a left. Rising up beside you is Laforet (laforet.ne.jp), which houses seven floors of strange, wonderful and, occasionally, wearable clothing concessions. The city's celebrated youth subcultures congregate each weekend, in their distinctive street-wear, on nearby Takeshita-dori: glam rock "Visual Kei", cute and fluffy "Kawaii", self-explanatory "Goth Lolitas" and more.
From Laforet, go back up Omotesando past Harajuku station and turn south at the National Stadium. Wander down through the park into Shibuya – home to Tokyu Hands (shibuya.tokyu-hands.co.jp), a destination department store that's equal parts John Lewis and Urban Outfitters, with a double shot of only-in-Japan. You could spend as many hours in here, learning about Japanese life, as in any similarly sized museum.
Make use of the landmark Shibuya pedestrian crossing (you saw it in Lost in Translation) to wend your way to Shibuya station, from which the Yamanote line will take you back to Shimbashi. You're now a short walk from the glossy designer shops of Ginza. And if you need perking up somewhere between Uniqlo and Bulgari, there's one more thing that you'll only find in Japan: here, in Starbucks, they serve lattes in "small".
The Tokyo Sky Tree (tokyo-skytree.jp/english) in Shitamachi, which has just been completed, provides the best view in Tokyo. At 634m high (2,080ft), it's the world's second-tallest structure (after the Burj Khalifa, in Dubai). There are two observation decks, at 350m and 450m, plus a shopping mall, aquarium and planetarium planned at its foot.
Food-lovers and rail passengers must visit "Ramen Street" in the bowels of Tokyo Station (tokyoeki-1bangai.co.jp/ramenstreet). Here there are eight ramen shops in the same thoroughfare, each specialising in a different noodle.
Tim Walker flew to Tokyo with British Airways (0844 493 0787; ba.com), which serves both Tokyo Haneda and Narita airports from Heathrow. Narita is also served by Virgin Atlantic, Japan Airlines and All Nippon Airways.
Tim stayed at the Shangri-La Hotel, Marunouchi Trust Tower Main, 1-8-3 Marunouchi, Chiyoda (0800 028 3337; shangri-la.com). Deluxe rooms start at Y51,944 (£404) per night, including breakfast.
Japan National Tourism Organisation: 020-7398 5678; seejapan.co.uk