The story begins with the protagonist, Hiiragi Seiichi, a second-year student at an idol training academy. Seiichi is the antithesis of an idol; he is unattractive, suffers from severe body odor, and has recently gained significant weight, making him a pariah at school. His only solace is his name, "Seiichi," which he feels is too cool for his appearance. He endures constant bullying, which he attributes to his appearance and the school's proximity to his home, coupled with its lenient admission policy.
During a lunch break, Seiichi is summoned to the back of the gymnasium by a group of male students who force him to run errands and use him as a punching bag. Despite the abuse, he is briefly helped by Hino Yoko, a beautiful classmate who treats him kindly, though he tries to distance himself to avoid implicating her.
Later, a mysterious broadcast announces that all students are to be transported to another world, a fantasy realm with monsters and magic, due to Earth's overpopulation. A disembodied voice, claiming to be a god, explains that this is a form of salvation for Earth and grants them basic abilities: status checking, an item box, and language comprehension. The students are given one hour to form groups for safer transportation.
Seiichi's classmates, led by Aoyama Hiroki, quickly form groups, but Seiichi is ostracized due to his appearance and the revelation of his abysmal stats, which are all a mere 1, except for his magic power. He is left alone. The god then announces that the groups will be summoned as heroes to a specific country, while Seiichi, being alone, will be transported randomly. As a parting gift, Seiichi receives the skill "Complete Dismantling."
Seiichi is transported to a dense forest. After an hour of wandering, he encounters a giant wolf, which he narrowly escapes. Three days later, starving and exhausted, he witnesses a group of "Clever Monkeys" dropping "Evolution Fruits." He manages to eat one, which surprisingly heals his scratched nails and fills his stomach, though it tastes terrible. He also discovers that eating unknown plants can grant him resistances, but often with severe side effects, like temporary paralysis from "Special Paralysis Grass."
Through continued exploration and consumption of various plants and fruits, Seiichi's stats begin to improve, and he acquires new skills like "Intermediate Appraisal" and "Poison Resistance." He also learns to craft items and discovers the "Clever Monkey's Knowledge" and "Acrowolf's Knowledge," which provide him with crucial information about the world, including maps and monster details. He also obtains skill cards, including "Cutting Leg," "Instantaneous," "Super Mixing," and "Tool Crafting: Master Class," and a "Water Attribute Magic: Extreme" card.
His body undergoes several painful "evolutions," significantly boosting his stats and granting him new skills and resistances. He also obtains a "Legendary" weapon, the "Water Spirit Orb Dagger," and an accessory, the "Night Bracelet," which allows him to see in the dark. He learns that killing monsters yields "drop items" like bones, fur, meat, and skill cards, and that his "Complete Dismantling" skill allows him to extract even knowledge and stats from defeated foes.
He eventually encounters a powerful "Kaiser Kong," a female gorilla who, despite her intimidating appearance and requests for marriage and children, is ultimately defeated by Seiichi's overwhelming body odor, which causes her to collapse. This event leads to further stat boosts and the acquisition of a "Smelly Performer" title.
Seiichi's journey continues as he navigates the dangerous forest, constantly battling monsters and acquiring new skills and knowledge, all while his stats and appearance undergo drastic, albeit often comical, transformations. His initial despair gives way to a grim determination to survive and adapt in this new, perilous world.
