The T in T-site stands for Tsutaya which is a chain of book and music stores. This location has extensive offerings of magazines, books on all topics, journaling supplies, and travel and food sections spread over a campus-like grouping of buildings. The location includes a shop for pets (you'll notice the leash hooks along the walkways,) a camera store that caters to women, and other lifestyle stores.
Following are some other places that I visited in Daikanyama that day.
Paletas makes popsicles/ice pops in very creative flavors.
Spring Valley Brewery
I don't really drink beer much. I don't like hops or bitterness so I'm limited to a certain range on the beer spectrum. Surprisingly, I liked every single one of the beers in the flight. Spring Valley Brewery is located at the beginning of the Log Road shopping area.
Daikanyama is a great neighborhood to walk around and explore without any particular destination in mind.