These photos were shot on a Saturday in the area informally known as Sanya (山谷) in the north-eastern part of Tokyo, between Minowa and Minami-senju on the Hibiya metro line.
Sanya is known for being one of the poorest neighborhoods in Tokyo. It's a very stark contrast to most other parts of this vibrant city. Here, most buildings looks like they might collapse any moment, and the streets are quiet save from some homeless people and old shopkeepers here and there.
There's also a high concentration of cheap "hotels" in Sanya, providing accommodation for as little as 2000 yen per night. most of the customers are people with few other options left, as a fixed employment as well as a guarantor (a person who takes financial responsibility in case the tenant doesn't pay the rent) are prerequisites for most regular apartments in Japan.