For those with an interest in fashion, Harajuku is the place for you!
While visiting Harajuku, a must-see spot is Takeshita Dori (in English, Tasheshita Street. Dori is the Japanese word for street). Takeshita Dori is the heart of Japanese street fashion and teen culture, according to Japan-guide.com. It is completely free to visit and in fact, an entire day can be made by walking around Takeshita Dori and taking pictures of the unique street style of Harajuku.
However, there's plenty of shopping to be done on Takeshita Dori. Some memorable stores are Daiso, which is the Japanese dollar store, and Flamingo which is a vintage/thrift store.
If you plan to shop, be prepared to spend lots of money, even at the vintage shops. Everything in Tokyo is expensive.
If you plan to travel in the summer, expect it to be scorching hot, and keep in mind that in Asia, not many places have air conditioning. So, dress in light clothing, bring a portable fan, and make sure to drink plenty of water. Water can be purchased at various vending machines placed throughout the streets of Tokyo. Water is very easy to find and is affordable, only costing about $1.