September 17, 2201 13:56, KYT, Western Trenches Second Lieutenant Rentarō Koizumi is sitting in the composite ceramic trenches built in the gentle wasteland devoid of any greenery. In the small trench, three subordinates are sticking to both sides of Koizumi, watching ahead. However, due to the drifting sand dust in the air, the visibility is poor and it is only possible to see up to two kilometers ahead. The radar is blocked by the sand dust, and it only displays short distances. In front of Koizumi, there is a massive conglomerate of composite ceramics. This is the surface layer of a multi-layered underground city. This city is home to six hundred thousand people. The enemy is approaching to invade this underground city, and it is the job of Koizumi and his colleagues to repel them. On the rooftop of the underground city, multiple gun platforms and artillery positions have been installed, turning it into an impregnable fortress. The trench where Koizumi is stationed is the front line to prevent the enemy from approaching the underground city. Koizumi is enveloped in composite armor, resembling a crude android. Without this armor, humans cannot survive due to the damaging effects of sand dust and radiation in the air. They must breathe filtered air. The three subordinates, however, are only wearing simple armor over their combat uniforms consisting of elbow guards, knee guards, gauntlets, shin guards, and helmets to protect their heads. The subordinates were humanoids born from an artificial uterus, genetically modified to adapt to harsh environments, capable of living in the wilderness amidst swirling dust and intense radiation without the need for protective armor. Koizumi's subordinates consisted solely of girls in their late teens. His helmet projects the map of the battlefield and troop deployment, displaying the slow advance of the enemy and combat prediction text scrolling down. Combat prediction. After the artillery battle, there may also be annihilation battles, and depending on the location, there may also be trench warfare. The fatality/injury rate is 5%. The fatality/injury rate never reaches 0% because it includes incidents such as friendly fire and accidental falls during combat, making it the practical minimum. Apparently, the headquarter seems to be confident in achieving a decisive victory. On our side, the First Infantry Battalion of about 300 soldiers is on trench defense. It is known that about 600 enemy forces are currently approaching, and there is a combat prediction indicating further enemy increase. Despite a two-to-one difference in strength, the battalion is overwhelming in terms of military power. This will be no problem. Furthermore, if we add the Third Artillery Battalion, which is positioned in the underground city towering behind the trenches, the enemy should no longer be a threat. The basic defense strategy involves annihilating the majority of the enemy forces with the main attack from the underground city and then picking off the few who have broken through the carpet bombardment. This defense strategy has not changed since Koizumi joined the army. The enemy has always used the same tactic: a frontal assault. It seems they lack any real strategy. Are they just acting on instinct? As there is still time until the enemy arrives, the 1111 squad of the First Platoon of the First Company of the First Infantry Battalion of the Japanese Army, under the care of Koizumi, remained calm. However, the leader of the 1114 squad stationed in the neighboring trench seems overly eager. You can tell from the incoming squad radio that he's agitated. Although the senior sergeant is trying to calm him down, he can’t manage it. His enthusiasm is getting the better of him. When I searched for the 1114 squad leader on the terminal, it showed warrant officer​ Katsuyuki Imori. His military record indicates that he has just graduated from the officer school and this will be his first battle. He has never defeated any enemies and seems to have a high sense of pride, without the capacity to listen to the opinions of the lower-ranking soldiers. The senior sergeant is trying to restrain his enthusiasm, but he is unsuccessful. He should have learned at the officer school to value the advice of the senior sergeant, but he seems too excited to listen. The other two members were privates. They were also new recruits and inexperienced. It seems that the only one useful in the 1114 squad is Sergeant Kuchinawa. This newly formed squad consists only of men on their first mission. The terminal history shows that during a patrol mission, the squad had an encounter with the Lunarians, and only Sergeant Kuchinawa was able to server. The other three were sent to the hospital and regrouped. It seems that this squad is about to become a weak point in the battle line. Despite his subordinates, Koizumi wanted to let out a deep sigh, although he didn't show it on his face. The reason Koizumi joined the military is simply because the distribution of basic necessities such as food, clothing, and shelter is prioritized for soldiers over civilians. If they don't join the military, many people will be sent to work in manufacturing factories all day. If one has high intellectual abilities, they will be assigned to either the administrative government, responsible for the operation of the underground city, or the judicial government, responsible for maintaining public order, based on their aptitude. Furthermore, those recognized as highly intelligent individuals will be engaged in some form of research at a research institute. For someone like Koizumi, staying quiet and repeating the same work every day was agony. However, he didn't achieve good grades in the military academy exams, so he was not able to hide in some research institute. Thus, Koizumi had no choice but to join the military. The current casualty rate in the military is quite low, and there is almost no chance of dying unless participating in special forces or special operations and being careless. Medical treatments have also significantly advanced, and one can undergo a regenerative procedure to restore lost limbs or receive a prosthetic replacement surgery. Furthermore, there are established techniques for organ transplants for internal and sensory organs. The only exceptions one had to be cautious about were the brain and heart. In the event of their destruction, there would be no chance for any kind of medical treatment. Surprisingly, the leading cause of death in combat is bleeding out. Blood transfusions are not possible on the battlefield. The ability to accurately and quickly stop bleeding determines the line between life and death. The casualties over the past year were in the double digits. The soldiers thought that they themselves would not be included in that number. And while it was not realistic, you could also stay unemployed. In this case, there would be no distribution of any kind, no salary, no housing support from the underground city's government, and no access to medical care or welfare. In reality, it would simply mean dying a lonely death. When humanity is living in an environment with limited resources, in such a harsh era, those without productivity or prospects for the future will be ruthlessly eliminated.

To avoid dying alone when unemployed, one must seek someone's protection, whether through marriage or having a lover. Furthermore, it was officially claimed that they did not exist, but there were rumors that some people were living as slaves. Suddenly, the battalion radio transmission from the headquarters became noisy with interference. "Report. From headquarters to all units. The enemy will soon enter effective firing range. Prepare for battle. Do not allow them to approach." Koizumi leisurely got up and took an assault rifle made of composite ceramics with wilderness camouflage leaning against the trench, pointing it at the enemy. Upon seeing this Koizumi's subordinates, the three girls, took the same posture. "Well, it's time to work. Let's shoot those who jump out first in sniper mode. There's no need to kill them. Aim for a sure hit on the torso. If we immobilize them, they'll get caught up in the artillery fire and die on their own. We don't need any headshot feats. Prioritize accuracy." "Understood." The three subordinates responded simultaneously, without any lag. Koizumi switched the assault rifle to sniper mode. The zoomed-in reticle was displayed on his retina, making the enemy's figure clearly visible. The weapon's aim was displayed on the retina from the gun camera mounted on the weapon. This allows shooting from any posture, reduces the danger of exposing oneself from the trench, and reduces the likelihood of the enemy knowing the shooting position. To be safe, mechanical malfunctions are also considered, and though the weapon itself is equipped with a simple sight like weapons from over 100 years ago, Koizumi had never used that sight except during training. The enemies appeared in Koizumi's view. They looked like a mix of beast and human, resembling both a wolf and a rabbit. The werewolf did not have a weapon. He was unarmed. The rabbit woman was holding a long sword. They are called "Lunarians". It's unclear whether it's true or not, but the story goes that they came from the moon several decades ago. The war between the Lunarians and humanity has been ongoing for several decades. But that is a story from before Koizumi was born. The Lunarians run at three times the speed of humans, zigzagging on two legs, and coming towards us. They seem to be cautious of sniping, showing an atypical intelligence for animals. It's the usual regular attack. The Lunarians attack the underground city about once a month in a regular pattern, but the Japanese army has repelled them many times. So far, they have not breached the trenches located in the north, south, east, and west. The attacking Lunarians always organize an army of the same size, use the same marching route, and employ the same strategy, so eventually, the front line came to be known as a predictable routine. "Warning to all units from headquarters. Artillery fire commencing. I repeat, artillery fire commencing." Immediately after, artillery fire from the underground city behind started simultaneously, illuminating the front line with dozens of light bullets shining quietly. Occasionally, the sound of exploding energy shells launched from mortars could be heard in the distance. Most of the weapons have been electrified, and the battlefield is quiet. What can be heard are mainly the cries of the Lunarians from a distance and the noise of collapsing on the ground. Watching classical war movies from over 200 years ago, it's almost laughable to see the use of primitive gunpowder weapons and the noisy battlefields they create, as well as the flawed weapons that run out of ammunition after firing only several dozen or even just a few shots. It has become nonsensical to use multiple different weapons for different situations. The current assault rifle can be switched between sniper mode, machine gun mode, three-shot burst mode, and single-shot mode with the press of a single button. There is no need to carry multiple types of weapons. Additionally by only using the engine part, it can be used as a pistol. About a hundred years ago, a mineral called Iwakram was discovered, which made it possible to obtain vast amounts of electricity, leading to an energy revolution. As a result, running out of energy has become inconceivable. But because imiaturization was prioritized, the amount of Iwakram used for weapons was reduced. So there is occasionally a need to replenish it. Nevertheless, there was almost no worry about running out of energy after just one battle. With the development of a weapon that can be fired almost endlessly and quietly, the form of warfare has completely changed. The battlefield became silent, with the moans of the lunar people filling the space beyond the laser beams. The vanguard of the lunar people melted, no, it seemed to be scorched by the initial volley. However, they did not falter and the lunar people's assault did not stop. Perhaps the lunar people have no fear. The barrage continues without ceasing, relentlessly firing. The tactical monitor displays a countdown to the start of volley firing. Ten, nine, eight, seven, six, five, four, three, two, one, zero. "Yes, it's time for work." Koizumi pulled the trigger as he spoke. Thin, short light bullets shot out from the assault rifle, piercing the heart of the werewolf that had escaped the barrage. Thanks to the laser weapon, there was no recoil, and there was almost no time lag between firing and hitting the target. Additionally, there was no need to consider the effects of wind or gravity. Therefore, there was no need to predict the enemy's movements, and the bullets instantly hit the targeted spot. Conversely, Koizumi thought that training with the simulator was more difficult. The three subordinates, without delay, began shooting in sync with the countdown. Following Koizumi's instructions, they prioritized accuracy, ensuring they incapacitated the enemies effectively. From other trenches too, hundreds of thin light bullets were fired, being soaked up by the Lunarians. The corpses of Lunarians were being mass-produced. Because they were shot through with lasers, there was no bleeding and they remained in a clean shape, but soon the corpses scattered limbs and organs due to the bombardment. However, since they were burned by high heat, no blood was scattered. The Lunarians are being shot down one after another right before our eyes, but their advance does not stop. Do they feel no fear or cowardice at all? His subordinates, Kikyou, Nabana, and Suzuran, are also steadily taking down Lunarians. The operational zone managed by Squad 1111 is reducing the enemy faster than the headquarters had predicted. The mission progress rate on the battlefield monitor is steadily increasing. However, the neighboring squad that Koizumi was worried about began to falter, unable to coordinate with the artillery and other squads. In their desperation to take down the enemy, they missed their attacks and started allowing the enemy to close in. Squad 1114's operation progress rate was not only below the average of other squads but was ranked the lowest overall.