In 2010, a self-dependent mining city in an uninhabited sacred island was constructed. During its inauguration in 2015, however, the entire island with hundreds of the worker and media crew disappeared into presumably other dimension. 52 years later, in 2067, human technology finally reached the point where they can established a dimension gate. Probes were sent to scout, only to return a message from the descendant of the then lost people.
The new dimension is habitable, with animals and plants that do not exists in the world. Though there is a problem: there are living inhabitants in that dimension, and during the 52 years, the [new continent human] has a lot of interaction with them, including marriages. The [new continent human] will only cooperate with the [earth human] after they are certain whether they will be treated as 'human' and have the same human rights under the Earth's law.
The Earth's UN Council debated over the policy, and then concluded that only after reviewing their cultures that they can make decisions.
And thus, the [new continent human] began telling their stories on what is it that they have been doing for 52 years in the continent where dragon rules the sky and magic run in the air.
