"Surround, surround the bird in a cage." Where is Okina Matara's beginning and where is her end? Which way is the future and which way is the past? As the back door god and a secret god, it's her who hides the truth. Have you learned to fly yet?

The Silk Road There are countless pieces of academic literature that describe the Silk Road. The Silk Road cut across Eurasia and, for hundreds of years, facilitated the trade of many commodities, predominantly silk. The Silk Road was, in fact, comprised of many routes and is often said to have been more of a concept than anything tangible. Not everything that traveled the Silk Road was a physical commodity, with technology, philosophies, religions, and other aspects of culture often being transported. The Silk Road can be thought of as a branching network of humanity's culture. The Hata clan is also said to have had strong ties to silk.

Gensokyo Reserve Theory Some theorize that Gensokyo functions as something similar to a nature reserve. This is because it has long protected humans and youkai from outside interference while preserving their ways of life. There have been several plots to invade Gensokyo for one reason or another, but each of them has ended in the decision to simply watch over it instead. And so, Gensokyo is the last peaceful land. Everyone knows that they themselves will eventually end up there, which is perhaps why they choose to protect it.

Gensokyo Planetarium Theory Many people live in Gensokyo. It's long history continues to unfold, and it has a diverse yet complex environment and culture. But what if it only appears that way? Perhaps it doesn't exist at all... No, that couldn't possible be the case.

The Land of the Back Door Movie theaters are equipped with movie projectors. They project movies from either behind the audience or behind the screen, and the story unfolds one scene at a time. But in reality, the entire story exists simultaneously on the film reel. The Land of the Back Door has witnessed all events in Gensokyo while exclusively observing its present state. Recording the changes from moment to moment would result in a huge amount of data. An unimaginable amount of data, in fact. People refer to things that are beyond imagining as fantasies.