The story begins with protagonist Jin'nai Yoichi, a 17-year-old who is considered a "failed hero" due to his lack of heroic abilities. He is summoned to another world along with 20 other classmates, all designated as heroes. They find themselves in the throne room of the Altoruga Kingdom, where Princess Iris, a young girl who lost her parents and brother during the summoning ritual, explains their situation. The ritual required royal blood as a catalyst, and with the remaining royal family being only Iris, the summoning of 21 heroes was the maximum possible. Their mission is to defeat a Demon Lord expected to appear in three years.
Yoichi's classmates react with a mix of confusion and acceptance. Haruki Yasogami, a charismatic and hot-blooded classmate, immediately volunteers to help if the world is in danger, but requests that everyone else be sent back home. Princess Iris regretfully informs them that returning to their original world is not possible, but legends suggest a gate to their world might appear after the Demon Lord's defeat. The heroes are then introduced to the "Hero Support Policy," which is explained by Prime Minister Geemul. This policy is not equal; heroes will receive personalized equipment.
The heroes are instructed to manifest their "Status Plates." While most heroes excitedly discover high stats and various skills and magic, Yoichi's plate is alarmingly basic, listing only "Strength," "Agility," and "Toughness" with low numbers, and his profession is simply "Hero." He also lacks any weapon skills or magic. To his further dismay, he discovers his primary weapon is a wooden sword. This stark contrast to his classmates, who boast impressive abilities and unique skills like "Treasure Box" and "Appraisal," leads to him being ridiculed and labeled a "failed hero."
Feeling ostracized and dejected, Yoichi leaves the castle. He decides to seek out a companion and heads to a slave merchant. There, he encounters Lati, a 15-year-old wolf-person slave with beast ears and a red collar, indicating she has the right to refuse sexual advances. Despite her rough appearance and the merchant's warnings about her being a wolf-person and having a red collar, Yoichi is drawn to her and purchases her for eight gold coins. He learns that Lati possesses the "Appraisal" skill, which he lacks, and also has combat abilities and magic.
Yoichi and Lati begin their journey in this new world. They face discrimination due to Lati's wolf-person heritage and Yoichi's perceived uselessness as a hero. They struggle to sell monster drops ("Earth Shards") at the Adventurer's Guild due to Prime Minister Geemul's interference, who seems to hold a grudge against Yoichi. They eventually find a sympathetic shopkeeper named Eile who buys their "Earth Shards" at a fair price.
Their adventures continue as they hunt monsters to gain experience and money. Yoichi's stats slowly increase, and he discovers that his "Hero" status grants a "Gift" that boosts his and his party members' growth rate. Lati proves to be a capable fighter and a valuable companion, often protecting Yoichi. They also learn about the world's unique culture, influenced by past heroes, including the existence of "Life Magic" and the peculiar sun that functions as a clock.
One day, while hunting, they encounter their classmate Kenji Kitahara, a "true hero," and his party being attacked by monsters. Yoichi and Lati intervene and save them. However, Kitahara and his noble companion, Gale, are condescending and ungrateful, further highlighting the prejudice against Lati and Yoichi's perceived weakness. Kitahara attempts to recruit Lati, offering to buy her and even suggesting she cut off her ears to hide her wolf-person heritage, which enrages Yoichi, leading to a physical altercation.
Following this incident, Yoichi and Lati continue to grow stronger. They discover that using Weapon Skills (WS) on monsters does not yield "Earth Shards," while Yoichi's direct attacks do. This leads to a more efficient hunting strategy. They also learn that Lati's "Appraisal" skill can assess the quality of items, revealing that Yoichi was sold shoddy armor.
Later, while at the inn, Lati is nearly assaulted by Gale, who is caught peeping on her. Lati incapacitates him, and Yoichi, fueled by protective instincts, rushes to confront Gale and Kitahara, who are revealed to be the ones who reported Lati for "slave violation." They are brought before Prime Minister Geemul and Princess Iris, where Yoichi is accused of sexual assault on Lati. Despite his protests and Lati's attempts to explain, he is restrained and his "Hero" status is deemed a curse. However, Princess Iris intervenes, pointing out the inconsistencies in the charges and the lack of proper legal procedure. She orders Yoichi's release and Lati's return to the slave merchant.
Yoichi, desperate to save Lati, uses his newly awakened "Acceleration" ability to escape and rushes to the slave merchant's. He confronts Kitahara, who is also trying to buy Lati, and defeats him. Yoichi then pleads with the slave merchant to let him buy Lati, promising to pay the remaining debt. The merchant, influenced by his brother's connection to Lati and Yoichi's earnest plea, agrees to a payment plan. Yoichi successfully rescues Lati, and they leave the slave merchant's together, their bond strengthened by the ordeal.
