This worldbuilding is an expansion of the original Sgt. Keroro universe, centered around my original Orikero, Togugu. As the very first original character I created, many of the world's settings, organizations, and storylines were developed around his life and gradually expanded into a larger narrative.
Planet Keron is roughly the size of Earth's Moon.
Unlike Earth, it has no oceans. Most of its surface consists of temperate wetlands suitable for amphibious Keronians. As Keronian civilization became increasingly advanced, the population gradually moved away from the planet's surface and into orbital habitats and floating sky cities. Today, the majority of Keronians rarely depend on their homeworld itself.
The wetlands are protected under the Natural Conservation Act, making them restricted areas where civilians are forbidden to enter. Many Keronians spend their entire lives without ever setting foot on the surface of their own planet.
The yellow star-shaped regions visible across Keron are floating sky cities, which have become the political and cultural centers of modern Keronian civilization.
Because Keron has studied Earth for countless generations—and has long viewed it as a future target for invasion—the shape of its continents has gradually evolved to resemble Earth's, almost unconsciously.
The Weather Control Facility
To better understand Earth's climate and seasonal ecosystem, the Keronian military constructed a massive Weather Control Facility deep within the protected wetlands.
The system artificially manipulates local climates, allowing regions of Keron to experience spring, summer, autumn, and winter—seasons that did not naturally exist on the planet.
Winter proved to be the most stable climate to maintain, eventually creating a vast snowfield that permanently covers part of the conservation area.
Once ordinary wetlands, these regions were transformed forever by the climate project. They remain under strict military control, accessible only to authorized researchers and specialized military units.
The snowfields are also inhabited by dangerous beasts whose origins remain unknown. Some believe they are escaped military bio-experiments, others suspect they are remnants of ancient Keronian research, while some argue they simply evolved independently within the isolated environment.
Lieutenant Colonel is one of the Keronian military's senior researchers.
Although he is not the highest-ranking authority, his extraordinary scientific ability earned him extensive permission from military leadership to conduct highly classified research.
His work focuses on bioengineering, environmental research, and the development of experimental lifeforms, while also contributing to projects surrounding the Weather Control Facility.
Over the years, he has overseen numerous experiments involving Keronians, including biological modification and organ engineering.
His primary laboratory is located within one of Keron's sky cities rather than on the planetary surface.
To the military, he is an invaluable scientist.
To many of his creations, he is the one who determined their fate.
Nikuku is one of Lieutenant Colonel's creations.
It is a fusion of a Keronian and intestinal tissue created through biological experimentation.
As a consequence of the experiment, Nikuku's intelligence and mental development remain permanently at a childlike level.
It was later assigned the role of disposing of corpses and biological remains.
Officially classified as a military sanitation unit, Nikuku is responsible for consuming and decomposing dead bodies, making it, in essence, a biological weapon designed for corpse disposal.
Snowfield Special Operations Squad
As the Weather Control Facility expanded, the military established a special unit dedicated to operations within the artificial snowfields.
Togugu serves as one of its members.
The squad spends long periods stationed inside the Weather Control Facility's snowfield zone and is frequently deployed to reconnaissance missions on other frozen planets.
Their duties include hunting dangerous beasts, environmental surveys, specimen recovery, and exploration of hazardous regions.
The squad currently consists of approximately five members.
Although they fight together, most of them have little attachment to Keronian society or even to Keron itself.
If one of them dies during a mission, few people would notice.
In many ways, they are both soldiers and forgotten people.
Togugu has gray skin, red markings beneath his eyes, a small scar on the lower left side of his face, and a fishhook-shaped scar on his abdomen.
He loves fishing, a hobby inherited from his father.
Both of Togugu's parents are officially listed as missing.
Whether they are dead or still alive remains unknown.
His father owned a fishing tackle shop, but when Togugu was still a child, both the shop and his father disappeared in a devastating explosion.
That incident permanently changed his life.
After losing his father, Togugu spent two years in an orphanage before being taken to a military youth training facility by Lieutenant Colonel.
As he grew older, he became increasingly isolated, stubborn, and emotionally distant.
He struggles to build relationships, feels little sense of belonging, and often displays violent tendencies while hunting or fighting.
Even after surviving life-and-death situations alongside his teammates, he rarely allows himself to truly trust anyone.
In this timeline, Togugu never abandoned his search for the truth behind his father's disappearance.
During his military service, he secretly investigated the explosion for years.
Eventually, he gained access to classified military documents that revealed information about his father's death.
The files confirmed what he had long suspected: the explosion had not been an accident, but was connected to the very military leadership that had controlled his life.
Years of suppressed anger finally erupted.
Using a whaling harpoon, Togugu brutally killed Lieutenant Colonel and five nearby Keronian soldiers.
He was arrested and sentenced to death for rebellion against the military, illegally accessing classified documents, and severe obstruction of military operations.
On the night before his execution, he dreamed of returning home after a day of fishing.
He held a large fish in his arms and ran toward his father, hoping to hand it to him.
But before he could reach him, the dream ended.
For the first time since becoming an adult, Togugu completely broke down and cried.
He realized that what he had truly been unable to let go of was not only his father's death, but the simple wish of returning home with something he wanted to share.
However, on the day of his execution, he discovered that Lieutenant Colonel had somehow survived.
His hatred for the military reignited.
He escaped execution and became a wanted outlaw throughout Keronian territory.
In this alternate timeline, Togugu never opened the classified files that would have changed his fate.
He never learned the truth about his father's disappearance.
Instead, he remained in the military and was assigned to the Snowfield Special Operations Squad.
Years of expeditions slowly pulled him further away from his past.
He spent his life traveling between the artificial snowfields surrounding the Weather Control Facility and countless frozen planets, carrying out hunts, reconnaissance missions, and patrols.
As time passed, every clue regarding his father was gradually buried beneath the endless snow.
Whether this was caused by hypothermia, the military-issued medication, or simply his own refusal to keep searching is impossible to know.
The unidentified drugs distributed by the military eventually became essential for maintaining his mental stability.
After prolonged use, he began suffering from dilated pupils, occasional strabismus, compulsive lip biting, and unconscious biting of his own hands.
His psychological condition steadily deteriorated.
Despite all of this, he remained an outstanding soldier.
He continued accepting orders.
He continued walking through one frozen world after another.
Eventually, he could no longer remember why he had joined the military in the first place, nor what he had once desperately wanted to find.
In the Outlaw timeline, Togugu discovers the truth—and with it, hatred.
In the Military timeline, he loses the truth—and eventually loses even the hatred that once defined him.
All that remains is a soldier who keeps walking through an endless winter.