Takashi Katori is a big fan of online games, and so is his American friend Sarah. However, one of their RPGs goes too far, as their virtual world and the Lezarion robot that Takashi created for the game somehow mix with reality. Takashi is caught, but later the Earth Governement discovers that an evil scientist from the Moon (now a sort of abandoned colony with restricted access) is hacking into virtual worlds and security, so they force Takashi to pilot the Lezarion and, with Sarah's help, fight evil and protect the Earth. (Source: ANN)

The story revolves around the members of a private military company (PMC), and the uneasy tension between them and the regular military after a war that caused massive environmental destruction. (Source: Animekon)

The World as we know it has been torn apart shattered by a series of natural disasters that have turned civilization into a brutish nightmare of survival and has left whole cities buried beneath the Earth. It's now a lethal and chaotic place, a place where only the strongest and most savage remain alive. The strongest of them all is a giant warrior known as Violence Jack… Violence Jack tries to avert a civil war brewing among the wretched inhabitants of a subterranean metropolis called Evil Town. Based on a character created by manga horror specialist, Go Nagai. (Source: AniDB)

Kanto Hell Earthquake has demolished the metropolitan completely. After the earthquake, Slum King is kidnapping girls and sell them as sex slaves. Mari is wandering on the devastated field looking for her lover, Ken. But she is also kidnapped by them. While she is tortured and trained as a sex slave, Ken saves her. Ken has become the member of Slum King. The king offers condition to him; in return for releasing her, he has to kill Violence Jack. (Source: AniDB)