The world is divided into two parts: 'The Building city' where the rich live, and the 'Hachon' where the poor live. Living in the 'Building city' with her family, Yuji dreams of moving to 'Hachon' one day. If she goes there, she might meet Seojin, who suddenly disappeared. Yuji's parents can't accept a reduction in wealth and are obsessed with their present lives. Yuji's siblin...