A poisonous fog destroyed human homes.
People live in protective shells made of special materials.
The technological world inside the shell is developing rapidly, but resources are tight and the human living environment is in danger.
Ellu is a girl living in the slums outside the shell.
Elu, who was dependent on her sister, had to work to support herself because of her sister's death.
But like her sister, Ellu was forced to become a member of the picket team and perform tasks outside the shell to find the hope of humankind.
But in mission after mission, Elu discovered the figure of a mysterious organization.
Many incidents are related to this organization...
Purpose: Live well no matter what