The story follows Yamashiro Rin, a sixteen-year-old Survivor, who is currently Level 1. In this world, monsters suddenly appeared on May 3rd, 2033, emerging from spatial gates and attacking humanity. While initial assaults were quelled by military forces, the monster attacks continued, drastically reducing Japan's population to eighty million. Concurrently, some humans gained supernatural abilities, becoming known as Survivors, organized by the government to combat the monsters.
Rin's unique skill is "Faker," which allows him to mimic one observed skill at a time. However, mimicked skills are only half as effective as their originals, making Rin's combat abilities weak. He primarily uses "Fog" for support, a skill he can only use three times a day at his current level. Survivors earn income by collecting "magic cores" from defeated monsters. Rin, working in low-level parties, earns a meager income, barely enough to support himself and send some money to his mother. Despite his weak skill, becoming a Survivor granted him a place to live and a basic living allowance, allowing him to attend school, which he values greatly.
During a mission, Rin's party encounters a Hobgoblin, a stronger variant of a regular Goblin. Their usual tactics fail, and the Hobgoblin overpowers them, severely injuring two party members. In a desperate act, Rin abandons his "Fog" skill and mimics the "Wave Blade" skill used by one of his injured comrades. He manages to stab the Hobgoblin repeatedly, miraculously defeating it. This feat, however, is attributed to luck.
The encounter proves to be a turning point. Rin's level increases to 2, and his "Faker" skill gains a second slot, allowing him to mimic "Wave Blade" and "Fireball." He begins soloing missions, successfully defeating Goblins and earning significantly more income. This newfound confidence and financial stability allow him to help his mother more and save money. He also aims to level up to be able to use his newly acquired "Lightning" skill, which he mimicked from a powerful Survivor named Kamiki Jin, but currently has zero uses due to his low level.
Rin continues to hunt Goblins, steadily increasing his income and experience. He reaches Level 3, gaining a third skill slot, and then Level 4, finally unlocking the ability to use "Lightning" once. This progression marks his ascent from the lowest ranks, with the ultimate goal of reaching F-rank and facing stronger monsters. He also experiences the satisfaction of saving civilians, a feeling that surpasses mere financial gain.
