The protagonist, Mayama Kayo, finds herself in a white void after dying in an accident while saving a creature that turns out to be a goddess's pet. The goddess, explaining that she cannot revive Kayo in her original world due to jurisdiction, offers her a chance to reincarnate in a different world with her memories intact as compensation. To survive in this new, monster-filled world, Kayo is granted one skill from a list presented like a video game interface. She chooses "Alchemy," inspired by her favorite crafting game, "Elise's Workshop," with the goal of opening a shop in a town and crafting items. The goddess also adjusts Kayo's physical body to the average human standard of the new world and fixes her dental issues.
Kayo awakens in a forest, dressed in unfamiliar, rustic clothing and equipped with a beginner's kit: a knife, a leather water bottle, and bread. Her first priority is to experiment with her skill. Upon wishing for an explanation, a translucent screen appears, revealing her skill is "Synthesis," not Alchemy. Disappointed, she discovers that synthesizing two identical "Circle Grass" results in "Amazing Circle Grass," which is still just a weed. However, she soon realizes she possesses an appraisal ability, as she can identify the "Circle Grass" and its properties. While she can appraise "Circle Grass," other plants remain unidentified. Through trial and error, Kayo discovers that synthesizing two "Uto Grass" allows her to appraise both the original "Uto Grass" and the resulting "High-Quality Uto Grass." She then experiments with synthesizing different materials, like grass and a berry, creating a "Conju Root" and learning to appraise the original "Potan Grass" and "Maruma Berry." She realizes her Synthesis skill, while not direct Alchemy, can create new items and, crucially, allows her to appraise the original materials after synthesis, effectively granting her an appraisal ability.
Kayo spends time gathering and synthesizing materials, upgrading their quality and expanding her knowledge of the local flora. She creates "Highest Quality Skuri Grass," a potent medicinal herb, and decides to head to town to sell her findings. However, she gets lost in the forest. As night falls, she is attacked by a "Fear Wolf." Just as she is about to be defeated, a giant, talking cat-like creature named Nyatto intervenes and saves her. Nyatto, a warrior of the "Nekko Tribe," explains that Kayo was in danger and offers to guide her.
Nyatto leads Kayo out of the forest to a road and then to the town of Trant. Upon entering the town, Kayo is treated as a child by the guards due to her small stature and Nyatto's fabricated story of her being an orphan rescued from monsters. She registers at the Merchant Guild, where she is surprised by the simple registration process and the guild's tiered membership system. When she presents her high-quality herbs, the guild employee is astonished by their quality and offers to buy them. Kayo sells all her collected herbs and spices, earning a substantial amount of gold, which she uses to pay the entrance fee and become a "Blue Merchant" to access banking services.
Nyatto, impressed by Kayo's ability to produce high-quality herbs, proposes a deal: he will act as her bodyguard and travel companion in exchange for her cooking delicious meals. Kayo agrees, and they begin their journey. Nyatto reveals that skill users are extremely rare, making Kayo's Synthesis skill exceptionally valuable and potentially dangerous if its true nature is revealed. He warns her to use her skill discreetly.
Kayo uses her newfound wealth to purchase a "Magic Bag" from a merchant, which she suspects is a scam. However, she uses her Synthesis skill to repair and upgrade it, making it as good as new. She then begins experimenting with synthesizing various ingredients, meticulously recording the results and expanding her appraisal knowledge. She discovers that synthesizing a poisonous "Udoku Grass" with other plants creates even more dangerous poisons, but also learns that combining them with a "High Potion" can create a "Lost Potion," a rare and valuable item.
Upon returning to the Merchant Guild to withdraw more funds, Kayo is met with surprise and whispers. The guild employee, believing Kayo was scammed, is astonished when Kayo reveals she repaired the "broken" Magic Bag using her skill. This incident further solidifies the rarity and potential of her abilities. Kayo continues to gather ingredients and experiment with her Synthesis skill, aiming to create valuable items and expand her knowledge of this new world. She also learns about the world's economy and the importance of quality ingredients, particularly in the context of medicine and food.
