It’s no secret that high-end fashion labels like Prada and Cartier have achieved a sort of mythical status in Tokyo. But here is something you may not know: Visiting their boutiques brings with it an extraordinary reward even if you cannot afford the dizzying prices of the merchandise. They provide, free of charge, a chance to experience some of the most spectacular buildings in the world.  In the last few years, many of architecture’s stars, including Renzo Piano, Rem Koolhaas, Toyo Ito and Tadao Ando, have been hired to design shops for luxury brands and have turned the city into a battleground for a rare, and spectacular, game of architectural one–upmanship. They have followed one award winner with another, one splashy statement with a splashier one. While Japanese architecture is known for its cool minimalism, these architects have thrown that out the window, creating sculptural symbols that are difficult to forget.  “The Japanese consumer has an insatiable appetite for the ‘new,’” said Naomi Pollock, Tokyo correspondent for Architectural Record and author of “Made in Japan: 100 New Products” (Merrell). “As a result, fashion brands hire architects to create novel, eye-popping boutiques that will lure shoppers.”  The best neighborhood for this type of “architectural shopping,” as I like to call it, is Omotesando, a leafy zone west of the city center, just outside the blurred neon craziness of Shibuya. Focused along its main spine, Omotesando (sometimes called the Champs-Élysées of Tokyo), it has long been a home to fashion boutiques and fine architecture.  The level of boutiques and architecture was elevated about a decade ago, when the Pritzker Prize-winning Swiss firm Herzog and De Meuron designed a breathtaking store for Prada on the narrower, more hushed, eastern end of Omotesando.  Prada’s facade is made up of large, diamond-shaped green glass pieces. The glazing is warped, creating fun house reflections and furtive peeks inside. From within the building, all that glass creates panoramic views of the neighborhood, framed by a diagonal patchwork quilt. The store’s interior design matches the exterior’s energy, with sleek, curving walls, sculptural built-in shelves and odd touches like mammoth suitcases and TV screens that seem to be growing out of gigantic extension cords. The building is slightly set back from the street and is built into a courtyard, surrounded by a folded wall.  This section of Omotesando has dozens of interesting buildings to gawk at. Just across the street the New York architect Stephan Jaklitsch designed a boutique for Marc Jacobs with a facade covered, in various sections, with smooth glass, etched black stone tiles and perforated steel. Around the corner a fractured, leaning structure contains several boutiques, including Chloé and Cartier. Bathing Ape’s store, around the next bend, is an exposed concrete frame covered by a glass cube; shoes fill up the entire second-floor facade. A space-age storefront by the British firm Future Systems for Comme des Garçons has warped glass walls and some of the funkiest merchandise on the street.  Once you head west, to the wider section of Omotesando, the thoroughfare becomes much busier, the sidewalks more crowded with swiftly moving masses. The first stop is arguably the best of them all — the Japanese master Toyo Ito’s Tod’s Shoes. In 2013, Mr. Ito won the Pritzker Prize, the profession’s highest honor. His store’s fractured, matte concrete and glass structure is inspired by the web of tree branches that line the street. Inside, the motif continues, with diamond-shaped walls that lean and list in varied directions. The interior feels very modern, but still warm and comforting.  You may not want to get too comfortable. The prices at this store — as at many others — hover between obscene and ridiculous. If you’re not in the market to shop, comparing the prices can be fun. The first item I examined, a brown leather briefcase, cost 136,500 yen, or about $1,130 at 116 yen to the dollar. The next, a pair of pillowing purple leather shoes, cost 60,000 yen. And those, it turned out, were the cheap ones.  Next door to Tod’s is a new building for Hugo Boss by the Japanese architect Norihiko Dan that resembles the turret of a castle, twisted and thinned into a listing chute. Covered with thin lines of grooved concrete, it appears to dance with Tod’s, like Frank Gehry’s Fred and Ginger building in Prague. Head west a couple of blocks and you will run into the Coach store, the work of another Pritzker winner, Rem Koolhaas. Here he has created a frontage of frosted and clear glass blocks that looks like a fancy white Rubik’s cube. Vitrines inside repeat this pattern, although less effectively. Head just a few more blocks west and you arrive at Christian Dior, designed by yet another Pritzker laureate, the Japanese firm Sanaa. The architects have created a tall, narrow light box: Windows are covered by translucent screens that ripple like curtains, so only colorful neon peeks through. Unfortunately the store has bulky, formal walls inside, so the look doesn’t carry through.  While you’re gawking at all these buildings, be sure to take in the shopping-unrelated surroundings. Meander behind these temples of fashion and you can explore winding alleys of strange and wonderful buildings, on a much smaller scale. Impossibly thick groupings of electrical wires, micro-thin streets and strangely stacked homes exist side by side with gargantuan edifices and broad boulevards. The best place to take it all in is the roof of the Gyre Center, a dark, angular complex designed by yet another famous firm, the Dutch architects MVRDV, right next to Christian Dior. Look over the balcony at the bustling, tree-lined street, and you also take in the scope of the seemingly infinite, super-dense skyline beyond.  Just down the street, the Japanese star Jun Aoki has designed a boutique for Louis Vuitton (one of a whopping 13 Louis Vuitton locations in Tokyo) whose facade’s varying squares of metal mesh are loosely patterned on stacked suitcases. Inside, the store is full of more art than many of the city’s galleries, including origamilike chandeliers and feather-light hanging steel filaments. The rooms are stacked unevenly, giving you the impression that you’re floating as you walk around.  Once you’ve had your fill of Omotesando, head about 15 minutes east on the subway into Tokyo’s version of Fifth Avenue: the Ginza neighborhood. Ginza is one of several tall neon canyons in the city, but more upscale than, for instance, Shinjuku, the area made famous by the movie “Lost in Translation.”  Here another world-famous architect, Renzo Piano, has built a narrow tower for Hermès, clad in nine stories of silky, bourbon-colored glass blocks. I don’t usually love this material, but in this case it’s a surprisingly striking solution. Look up and you become entranced; it seems as if you could walk right up the side. In the interior, the translucent blocks lend the display spaces a warm glow and create a show when lights mysteriously change color and form behind. The effect is particularly strong on the top floor gallery, with its extra tall floor-to-ceiling glass. Again if you want to go shopping it will cost you. A leather iPad case, for instance, goes for $554, more than most iPads.  A few blocks down the street are two more eye-catching stores. Jun Mitsui’s tower for the jewelry company De Beers has a gray steel facade that warps in and out in broad curves. It’s as if you are looking at a modern office building while very drunk, as more than one onlooker said to me. The interior is like any other store from the chain, but it’s still fun to look at diamonds worth over $100,000 now and then.  Down the block Mr. Ito has designed another jewelry boutique, Mikimoto, a stunning paper-thin white tower cut with large amoeba-shaped windows. I call it the Swiss cheese building, for obvious reasons. The displays inside match this exuberance, with bubble-glass chandeliers, sparkling filaments and crystals, and bright blue and white walls. The third floor has a sleek cafe, and if you’re getting married (or want to pretend to), take a turn at the bridal area for high-class fantasizing.  It’s fun to browse more of the amped-up architecture in this area, including the spectacular LED light shows of Chanel, Max Mara and Matsuya, as well as the etched metal facade of (two more) Louis Vuitton boutiques. And, as they say in retail, there’s so much more.  Not every new boutique is a triumph. Many resemble the cookie-cutter locations you see in retail districts around the world. Even masters like Tadao Ando have their clunkers. His new Omotesando Hills mall shows off his stunning exposed concrete walls, so smooth you feel as if you could eat off them. But in the end it still feels like a mall. Many local architects complain that these high-end follies are not serious architecture, but gimmicky flash. In many cases they are right. But that’s O.K. Form, as any architect will learn, follows function. In this case it’s selling a name and a mystique.  A version of this article appears in print on February 7, 2016, on page TR11 of the New York edition with the headline: In Tokyo, Splashy Architectural One-Upmanship. Order Reprints| Today's Paper|Subscribe
Star architects have created so many high-end stores in Tokyo that it’s worth visiting two shopping districts where the best item — eye-popping building design — is free.