Gibiate

The anime takes place in Japan in the year 2030. Humanity is confronted by an unknown and deadly virus that turns people into monsters, with the form each victim takes depending on their age, sex and race, which terrifies everyone. People try to find a cure but suffer failure after failure. The virus has been named "Gibia," a name that echoes the French word for game, as in hunted animals. Scientists are searching for an antidote to save humanity, but time is running out as the number of infected keeps growing.

It is at this moment that two people from the past arrive in a ruined Japan: the samurai Sensui and the ninja Kenroku, warriors from the early Edo period. Some force has sent them into the future to help a professor, Dr. Kathleen, who is working on a cure for the virus.

Now the two heroes, accompanied by the doctor, must travel across a devastated, desolate country full of dangers, fighting countless Gibia monsters, outlaws and other fierce foes. The two warriors must protect her, because she is the last hope for all of humanity. How will their journey to save mankind end?