It looks like this apartment, where a friend once lived, is available again on RealTokyoEstate (or Tokyo R Fudosan) — a great site for oogling odd living spaces.
This apartment looks tiny and it is, sort of, and that’s a wall right outside the window. But it feels larger than it is, thanks to overgrown trees and shrubs on all sides. You have to walk down a green path to get to it, which is odd, because this place is no more than three minutes from that bridge where all the weekend Gothic Lolitas gather in Harajuku. Call it one of those weird time/space eddies you can still find here and there in Tokyo.
On second look at the ad there is no wall. The apartment for rent is the one a floor above, so if you move in, you also get a view of the Yamanote Line.