is a Japanese anime television series produced by Sunrise's internal "Studio 7" and JVC. It is a spinoff of The King of Braves GaoGaiGar, produced under the direction of Yoshitomo Yonetani and writer Hiroshi Yamaguchi. It aired on TV Tokyo from April 1, 1999 to September 30, 1999, and was the first anime to broadcast in widescreen, though it was letterboxed.
Plot
The year is 2006, a series of seemingly random terrorist attacks rock the globe. Dubbed "Algernon", normal people suffer psychotic breaks and begin murdering everyone around them - often in profoundly disturbing fashion. In the wake of traditional law enforcement's failure to turn up any link between these incidents, a private contractor known as Akamatsu Industries is brought in to explore if Algernon is a disease, an unknown terrorist group, or even more exotic possibilities.
Meanwhile, a mysterious mass fatal accident occurred while preparing for the opening ceremony at the geofront type underground amusement park "Bottom the World". Asami Toko of the Algernon research institute "Modi Warp" who visited the investigation with the authorities, concluding that the accident was caused by Algernon. Around the same time, high school student Keita Aono accidentally stumbles inside the prototype Neuronoid Kakuseijin 01 in which is piloted by a girl named Hinoki Sai, his childhood friend he hasn't seen in years, and on board the cockpit as a rare "Dual Kind" head diver. In their exploration in the "Bottom the World" in hopes for them to escape, they both find out the mystery behind the Algernon phenomenon and the mysteries surrounding the mysterious man named Lamia who is classified as a "Betterman".
Shared continuity with The King of Braves GaoGaiGar
Betterman takes place in the same world as The King of Braves GaoGaiGar, predominantly before the events of The King of Braves GaoGaiGar FINAL, though only a few minor links are visually made within the series itself. The novel series King of Kings: GaoGaiGar VS Betterman fully explains the connection between two series and how both events overlap each other.