Outside the black wall means death, inside the white wall means civilization,
And countless people like Cheng Nuo were born in the gray area between the black and white walls.
He, they, have been waiting for an opportunity,
Explain yourself, explain the world.
Many years have passed since my parents left.
And today Chengnuo himself will embark on a journey;
He will travel to the end of the world and eventually return to his hometown.
Starting today, set out to save the one you love together with the one you love.
Concept: In a fantasy world, the adventure and growth history of boys and girls born in gray areas.