A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja.

Asami returns exhausted after three years of intense training to become a yakuza hunter. She decides to visit her old master, Inokuma, who runs a bar. However, she finds his place in ruins and nothing is as it was when she left. As it turns out, the local yakuza had turned it into a gambling house and laid claim to the entire area with the help of a cold-blooded killer named Akira. Akira is relentless, and utilizes cruel tactics when anyone dares get in her way.

11-year-old Yusuke and his classmates camp in the woods and see a strange light. They discover a small metallic object like a robot which talks, calls himself Tetra and knows Yusuke's name. Tetra can create wonderful gadgets but actually has to save the world with Yusuke's help from extraterrestrials with bad intentions.

A young woman from the future forces a local gunman to help her stop an impending alien invasion which will wipe out the human race.

In 2199, five years after the Gamilons began an invasion of Earth, the planet has been ravaged by the aliens' bombs. The remnants of humanity have fled underground to escape the irradiated surface. One day, former pilot Susumu Kodai discovers a capsule sent from the planet Iscandar that tells of a device that can remove the radiation from the Earth's surface. The Earth Defense Force rebuilds the battleship Yamato with a new type of propulsion system to make the 148,000 light year trip to Iscandar in hopes of saving the Earth. Within one year, the radiation will drive the rest of humanity to extinction.

In the year 2011 the greatest tectonic disaster in the history of mankind has occurred. As a result of the catastrophic earthquakes North and South America, Eurasia, Africa and Australia have sunken underwater while the Japanese islands remain untouched.

The story is about a woman named Asami who is tortured and left for dead by a Yakuza group, only they failed to finish her off, and she staggers back from the grave, literally. Bruised and battered, Asami seeks refuge at her old gang until such time she is ready to take on the Yakuza and go face to face with Junko.