The protagonist, a low-ranking copper-tier adventurer, struggles with poverty and a lack of fulfilling quests. One day, while returning from a job, he discovers a mysterious, seemingly bottomless hole in the road. Feeling disillusioned with his life, he throws his beginner's staff into the hole. Suddenly, a woman in white robes emerges from the hole, floating, and presents him with a golden staff, then a silver one, and finally his wooden one, asking if they were what he dropped. He denies dropping any of them, fearing punishment. The woman, calling him a "contrarian," then offers him the hole itself before vanishing. The hole also disappears, leaving the protagonist bewildered.
Returning to town, he is confronted by loan sharks demanding repayment. He explains he has no money, having failed a goblin-hunting quest due to encountering a Hobgoblin, which would incur a penalty if he reported it. As the loan sharks prepare to break his fingers, a hole suddenly appears beneath one of them, swallowing him. The protagonist realizes the woman's parting words about the hole were true. He experiments, creating holes under two more of the loan sharks' subordinates, who are also swallowed. The remaining loan shark, intimidated, demands to know how much he owes. He learns he owes a substantial amount in silver and copper coins, including exorbitant interest and "handling fees." He attempts to negotiate a lower amount, but the loan shark, revealing himself as part of the "Gazura Family," threatens him. The protagonist then creates a hole under the loan shark, who is swallowed. A giant blue-white hand emerges from the hole and drags the loan shark in completely.
After this incident, the protagonist's luck dramatically improves. He completes all his quests, his guild rank rapidly increases, and he becomes wealthy. He attributes this to the "hole" power, believing the mysterious woman was a god. He discovers the hole can absorb anything he desires, from objects to clothing, without harming him or the owner, but he cannot retrieve anything once it's absorbed.
A new quest appears on the guild board: to investigate a series of incidents where young women are having their clothes mysteriously removed. The protagonist dismisses it as beneath him, wanting a more challenging quest. Suddenly, a man in ornate armor, identified as a renowned hero named Yuto, shoves him aside to take the quest. Yuto is surrounded by adoring female companions. Yuto throws the protagonist some copper coins, calling him "low-class." Enraged, the protagonist creates a hole above Yuto, who is swallowed. However, Yuto reappears, having flown out of the hole. A struggle ensues between Yuto and the hole, with Yuto eventually gaining the upper hand. The protagonist then summons more blue-white hands, which also fail to hold Yuto. Yuto then slices them with his sword. The protagonist creates another hole above Yuto, who is then sucked upwards and disappears. Yuto's companions are distraught.
The protagonist is summoned to the Adventurer's Guild for an emergency meeting regarding the disappearance of Yuto and the frequent incidents. He falsely claims a Demon Lord is responsible, causing panic. Yuto's companions refute this, stating Yuto sealed the Demon Lord. The protagonist insists the Demon Lord is seeking revenge and urges everyone to flee, causing many to evacuate the guild.
Later, the protagonist is forced to join a group of adventurers, including Yuto's companions and several gold-tier adventurers, to investigate the Demon Lord's seal. They travel to a dilapidated castle, the Demon Lord's former residence. During the journey, the protagonist's slow pace, due to his copper-tier stamina, draws criticism from one of Yuto's companions, who suspects him of foul play.
Upon reaching the castle, they find the seal intact. However, one of the gold-tier adventurers, Brasdy, reveals himself as a traitor and stabs another adventurer, Jay, with a "Demon Sword," which prevents healing. Brasdy explains he was working for the country, which had a pact with the Demon Lord to maintain balance by using monsters and suppressing internal dissent. The country had ordered Yuto to seal the Demon Lord when it became unruly, and Brasdy's goal was to break the seal to restore the Demon Lord's power and weaken the Adventurer's Guild. The protagonist uses his hole ability to absorb the Demon Sword's curse from Jay, allowing him to be healed.
Brasdy is captured, and during his interrogation, he reveals the country's long-standing alliance with the Demon Lord. He explains that the Demon Lord is reborn when killed, so sealing it was the only way to manage the situation. He also reveals that the country provided the Demon Sword to Yuto to seal the Demon Lord, as the Demon Lord was becoming too independent. The protagonist realizes Yuto and his companions likely knew about this arrangement.
The group prepares to fight Brasdy, who is now outnumbered. The protagonist uses his hole ability to disarm Brasdy and strip him of his armor and clothing, humiliating him. Brasdy surrenders. The protagonist then uses his hole to absorb the curse from Jay, allowing him to be healed. Brasdy confesses that the country ordered him to break the seal. The protagonist, realizing the complexity of the situation and the potential danger, uses his hole to absorb the magic circle and the nascent Demon Lord before it fully emerges, saving everyone. The other adventurers are astonished by his power.
