A reinterpretation and adaptation of Hara Tetsuo's original series "Hokuto no Ken" (Fist of the North Star) and "Hana no Keiji" (The Legendary Hero), which aired from 1988 to 1989, featuring new artwork by Yoshihara Motoki. The narrative in Cyber Blue: The Lost Children revolves around Blue, an offspring of settlers from Terra who migrated to the far-off planet Tinos during the 22nd century. Due to the harsh conditions on Tinos, humans are forced to depend on a biomechanical life support system implanted in their chests called Biomatrix to survive.
In the 25th century, Tinos is governed by an authoritarian Planetary Government that seeks to eliminate The Lost - individuals who refuse to comply with its oppressive rule and are hunted down mercilessly by its military for extermination. To maintain control over Biomatrix production and distribution, the government issues them only to those who submit to their authority. As a result, the Planetary Government aims to eradicate The Lost and their descendants, the Lost Children, once and for all.
The story unfolds in the dystopian setting of Junk City, where Blue encounters Fats, a powerful robotic Artificial Intelligence. Their encounter will have profound implications on both human and machine existence, as well as the fate of the Lost Children and the trajectory of human evolution.