Baocheng is a medium-sized industrial city that is out of touch with the development of the times and densely populated. The sound of machines operating can be heard all day long. Xiao Hei and Xiao Bai are called "cat party". They can fly on the top of the city and slide down in the deep space. Xiao Hei will use an iron rod to beat up adults he doesn't like, while Xiao Bai has his own naive imaginary world. Baocheng is a city without a future. Until a company called "KIDDYKASTLE" came here and wanted to transform Baocheng into what they wanted, the bad kids knew that it was time to fight for their lives and the city, and even for their souls. The city's lack of rules, freedom, fresh air, and amusement facilities are all unique to Baocheng!