For years, the worldwide conglomerate known as Orion Corporation, renowned for both their innovations in the world of technology, as well as their many dubious experiments, has been secretly conducting a bunch of experiments regarding "fight data" and has since collected data from fighters all around the world for use in their bio-weapons, leaving them for dead once they're done.
At the center of the story is Shin Ikushima, the only son of Shiho Ikushima, a renowned master in the art of Kyokushin karate during her prime. He grew up under the guidance of his mother, with his father having left Shiho right before he was born. Realizing his potential, Shiho decided to teach Shin the art of Kyokushin karate at a young age.
Shin used to live a peaceful life with his mother until one day, a group of Orion soldiers barged in their house and tried to abduct Shiho. However, Shiho fought the soldiers until she was taken down, and ultimately killed, by a shot to the head fired by one of the soldiers. He has since grew to despise Orion and trained himself in order to exact his revenge and avenge the death of his mother.
Years later, Orion announced the first Sentoki: Global Martial Arts tournament, where various martial artists gather around to prove who is the strongest of them all. Shin decides to join the tournament in order to destroy Orion by himself.
However, what Shin did not realize is that the tournament was was actually a ruse for Orion to collect more fight data in order to unleash their ultimate weapon: the bioweapon "Antares".
