[Update: closed.] The setup at this rescue-cat cafe is quite minimal - a few perches and climbing trees, some lockers and vending machines and a few seats for visitors, a handful of cat-themed magazines and just a few cat toys. There's a radio playing in one corner.
Most important though, they do have a lot of cats - some two dozen when we visited, including several kittens - and the atmosphere was more lively than expected, with lots of dramatic chases and thrilling acrobatic performances.
The cafe is a bit off the beaten track, so you may find a higher cat-to-human ratio than at other more centrally located cafes. It's located right above Iwamotocho station on the Toei Shinjuku line, and close to Akihabara station on the Hibiya line.