Monochrome Street is an area accessed by Red Streetlight World, to access this area, you need to find a streetlight with two lights at right side.
From the main entrance(the small streetlight), go right until the first streetlight, when you came close to it, go south and you'll see this streetlight, interacting with it, you'll be transported to this area.
Features
This area contains some reflexive things, like arrows, houses and more. Going left until the next arrow and taking north, you'll be in a area with lots of houses, in one of them has a portal to Shinto Shrine.