They are the humans that live in the outside world.

While they come from the outside world and have different clothing, hairstyles and speech patterns, there is no clearly defined difference from the people of Gensokyo.

Most of these humans are in a state of panic, but it should be natural.

The knowledge they possess is far more profound than ours, and they handle tools yet unknown to us.

Both the humans and youkai of Gensokyo are easily influenced by the outside world, and when they learn something new from an outsider, that will become popular for a while (*1).

Most outsiders that get caught by youkai either get eaten at once, or get eaten once the youkai lose interest in them.

If an outsider has the luck to reach the human village, they can be returned safely to the outside world if they go to the Hakurei Shrine.

However, there are also rare cases where outsiders settle into Gensokyo.

Such outsiders are treasured, since they hold unique knowledge.

1: Lately, a sport called "soccer" has become popular. In this manner, Gensokyo is halfway infected with the outside world.

*They immediately put a tool called a "mobile phone" to their ears, and after that are at a loss as of what to do next.

Perhaps this tool emits sinister sounds.

*Even if they see youkai, they will neither run nor fight.

They are willing to become eaten.

*In spite of this, if they see a ghost they'll run away at full speed.

Even though they are less dangerous than youkai...

*They hold little knowledge about the outside world.

Despite using those tools, they know little of the theory and construction of them.

The mobile phone is an example of this.

Therefore, it is impossible to reproduce the tools of the outside world in Gensokyo. Regrettable, indeed.