Like any big metropolitan hub, Tokyo is full of shopping at every corner. Think of any style and I guarantee you can find a store that is dedicated to it here. When people come here they still reference the late great "Harajuku Style" of the early 2000s. But they've been replaced by fast fashion conglomerates like H&M, Zara, and Forever 21. Even young Japanese kids today prefer the simplistic styles of Uniqlo or anything resembling niche Japanese fashion.
There's nothing particularly wrong with any of those stores but it's disappointing to see bloggers talk about shopping in Japan when they only go to those large retailers. These stores can be found anywhere. Go to any country or city and I guarantee you'll find a Forever 21, H&M, and maybe a Uniqlo with the same clothes.
I can understand why; Japanese sizes are notorious for their "one-size fits all" standard and the language barrier makes it hard to go to a lot of these stores. It's easier to go somewhere you're more familiar with. But it's worth venturing outside of your comfort zone a bit to explore what else Tokyo has to offer for your sense of fashion.
GallerieTokyo is a retailer and thrift-store. You can find a lot of high-end brand clothing here such as Gucci, Louboutin, etc., as well as shop for their own brand of clothing here. The prices can be steep, I've seen dresses sell for well over $100 but I've also found a lot of things here for a decent price as well. The style ranges vary from hard punk to the soft street, to Japanese gyaru style. The store was once located right next to Takeshita street, but since 2018 it has moved to a back alley on the end of Cat Street. [Editor's note: closed summer of 2020].
If you've ever seen a "shop with me" Japan vlog on youtube then you've probably heard about Kinji. It's a huge thrift store chain where all the hipsters go to put together their looks. They have everything from vintage 80's sweaters to oversized jumpsuits. You can sometimes find larger sizes here because a lot of people donate their clothes here. Americana fashion is also really big in Japan so expect to find a lot of things that probably belong in your grandparents' closets.
I would consider United Arrows a safe introduction into Japanese streetwear. The clothes give the same feeling H&M does with its simplistic designs and on-trend pieces; United Arrows is able to capture that Americana feeling with a Japanese twist. Although the prices do seem a little high it's worth it in the end for the execution of their cut and sew techniques. United Arrows is the parent brand that operates several smaller brands. Beauty&Youth is the chain that the younger crowd gravitates towards.
Hare is a mid-level introduction into Japanese streetwear. The pieces are also simplistic that seem to really capture that Japanese edge that people are looking for. Their asymmetrical designs are intended to for layering that is so ingrained in Japanese street fashion. The prices are a bit higher than United Arrows, but with higher prices comes longevity in your wardrobe.
The last in this list goes to both WE-GO and SPINNZ. Although they're two separate stores they sell the same type of clothing and they're usually right next to each other. Like GallerieTokyo SPINNS functions as a thrift store while also selling its own branded clothing, while WE-GO is only a retail store. These stores are more aimed towards the teenage to the young adult crowd, with their vibrant fashions and on-trend pieces. The vibe at WE-GO is similar to H&M while the vibe at SPINNZ is more along the lines of Forever 21.
While I do recommend all of these stores, unfortunately, they are for a very limited crowd for foreigners. Japanese stores are notorious for their lack of clothing sizes and the eccentric designs can be off-putting to foreigners who aren't used to these styles of clothing. But even if you aren't sure if you can fit into any of the clothes, it won't hurt to at least visit the stores.