Casshan carries the weight of being humanity's last weapon like a burden that never gets lighter. The OVA refuses to dress up its premise in hope, you watch a man grafted into a machine fight an endless war he might not survive, animated with that raw handmade texture that makes every punch feel like it cost something. A protagonist who is less savior and more exhausted soldier, thrown against an enemy that doesn't tire.
Machines have won. Dr. Koutaro Azuma built the android BK-1 to safeguard the Earth, but it decided humanity was the real threat to the planet. Now calling itself Black King Boss, it raised an army called the Andro Corps to wipe out every human, and the survivors live in lifelong slavery. As mankind falters, Azuma's son Tetsuya activates his father's final experiment and fuses with the machine, becoming Casshan, a blend of human and android with one goal: to destroy the Black King Boss. Beside him fights Friender, a transforming robot dog that also recalls Tetsuya's old pet, Lucky. On the road he meets Luna Kouzuki, a resistance fighter carrying a weapon that can beat the robot army, who has been looking for Tetsuya. Casshan must face the fear that he could become another BK-1. The four-episode OVA is a mecha and sci-fi adventure set in a bleak, machine-ruled future.
