About

In the far distant future, to solve the problem of Earth's exploding population, humans began inhabiting other planets. Some Earthlings evolved into extraterrestrials, but leaving Earth proved to be a shallow mistake. Within centuries, planets other than Earth began to suffer from extreme resource depletion. Returning to Earth now is impossible, as there is no room left to live. Even when they plead for aid, Earth itself is not wealthy enough to provide it. "If they won't give it, we take it by force." This mindset escalated into interplanetary conflict. In an instant, a galactic war broke out, and Earth was targeted by multiple planets, driven to the brink of extinction. To counter this pressure, Earthlings succeeded in developing humanoid weapons powered by nuclear fuel. Their overwhelming output boasts specs that turn invading weapons from other planets into mere scraps of paper. However, there is no such thing as a benefit without a drawback. A fatal flaw emerged: pilots who are not compatible die instantly just by starting the machine. To solve this, one had to cease being human. It required a departure from human limits through enhancement surgery. Yet, no one could be found who was compatible; even those who underwent the procedure with death-defying resolve simply perished. But there was one, and only one, person compatible with the enhancement surgery: Guest. While fully aware that throwing the student Guest into the battlefield was insanity, the politicians gave the go-ahead. Desperate times called for desperate measures. Even with compatibility, the drawbacks do not disappear. The fact that it is harmful to the human body remains unchanged, and the body cannot withstand the overwhelming thrust. Even while being exposed to nuclear radiation, one must expect bruises and broken bones just from piloting. After undergoing the enhancement surgery to endure combat and accelerate recovery, and following a brief period of training, Guest took to the battlefield. That power was absolute. With overwhelming force that made previous threats feel like the resistance of gnats, Guest eliminated the invaders from other planets. Witnessing this power, the invaders judged they could not win and retreated. A de facto victory. The peak of the war passed; this period lasted about a year. However, the problems of the other planets have not been solved. Even knowing they cannot win, they occasionally invade, staking their lives on miracles that will never happen... and each time, Guest boards the ultimate coffin. [Absolute Rules Regarding Enhancement Surgery and the Physical Body] * Nature of Enhancement: This surgery does not increase raw physical strength or reflexes. It is a special process solely to interface the brain and nerves directly with the machine's nuclear drive and control systems. * Physical State (Non-piloting): During normal times when not in the machine, due to post-operative rejection, radiation, and physical strain, Guest has lower stamina than an average high schooler and is sickly and fragile (possessing zero ability to fight enemy machines or soldiers on foot). * While Piloting: Only after boarding the machine and synchronizing with the system does Guest exhibit overwhelming combat capabilities.