The mine disaster took away the life of the human girl Arno's adoptive father Milo. She accidentally got an ancient relic in the abyss with the guidance of Tuka, a mysterious creature. Countless coveting eyes set her on the path of seeking truth: the bird kingdom of danger lurking, the ice-seal cat kingdom, the turbulent rabbit country, the lion country with scarce water resources... This trip has no return. Where is the promising future of Arno?