High school student Masato Jinguu has always had a fondness for animals. Since childhood, he visited the zoo and even formed a friendship with a young elephant named Hanayo. He returns after seven years to find the zoo transformed into Fuji Safari World, a place where visitors can interact closely with the animals... but that is not the only change. When Masato brings his old friend Hitomi to visit, they discover that the zookeepers are being attacked by the animals. Upon finding Hanayo's caretaker, Nakata, they realize the horrifying truth: the animals possess human faces! Now, the animals are seeking revenge for being subjected to cruel experiments...