The protagonist of the game is a college student named Yuuji Shibata. One evening, just after hearing on the news that someone has stolen a tiger, he goes out to a convenience store. On the way back, in a dark alley, he notices a strange creature, a young girl with cat ears and tail. She doesn't seem to remember anything …

The fourth entry in the GaoGao series is set in the same post-apocalyptic world as the two previous games. In the future, a failed biological experiment caused widespread mutations, leading to a total separation of human civilization and the mutated tribes of "animal people". The events of the game begin shortly after the end of the previous installment. Human civilization …

A biological experiment that began in 1993 led to a terrible disaster in the beginning of 21st century. A virus that turned living beings into mutants and monsters has been unleashed. Soon the Earth turned into a terrifying place of chaos, as more and more human beings became infected. Unspeakable violence obliterated human civilization. Within a few years, humanity was …