The story begins with the protagonist, Ryota Sato, waking up in a dimly lit, brick-lined underground space, disoriented and confused. He is immediately confronted by a small, young girl named Emily Brown, who wields a massive hammer and speaks in game-like terms, referring to Ryota as a "drop" from a "rare slime broth." Ryota, a former salaryman who collapsed from overwork and was subsequently fired, finds himself in a world where all objects, from vegetables to metals, are obtained by defeating monsters in dungeons. Emily, a seemingly naive but surprisingly strong individual, explains that this is the norm in their world.
Ryota learns that this world operates on game-like mechanics, with monsters, drops, and a "Nowboard" that displays character stats. Emily, a power-type character with low speed and dexterity, focuses on farming "sprouts" by defeating slimes in the first basement level of the Telur dungeon. Ryota, upon checking his own stats, discovers he is level 1 with all stats at F, except for "drop stats" which are all S. Emily, despite her low stats, is skilled in combat and cooking, and her kindness deeply impacts Ryota. He decides to help her by earning money through farming sprouts, which he sells in the nearby city of Cyclo.
Ryota's exceptional S-rank drop stats allow him to efficiently farm sprouts, earning enough to rent an apartment for Emily. He also discovers that in the Nihonium dungeon, he can defeat skeletons to obtain "seeds" that increase his HP, and later, in Telur's second basement, he gains the ability to increase his strength by defeating zombies. He acquires a revolver and bullets from a "rogue monster" (a monster outside a dungeon), which proves invaluable for combat.
Ryota's life becomes a routine of dungeon diving, farming, and returning to his comfortable home with Emily. He encounters various characters, including Elza, a shopkeeper who offers him good prices for his drops, and Eve, a bunny-eared girl who is obsessed with carrots and possesses incredible combat abilities, capable of defeating monsters with a single "chop." Eve's unique abilities and her peculiar interactions with Ryota add a layer of mystery and humor.
As Ryota delves deeper into the dungeons, he faces increasingly challenging monsters and discovers new mechanics. In Telur's third basement, he encounters "Cocro Slimes" that drop pumpkins. Emily, usually gentle, displays a terrifyingly fierce side when dealing with these slimes, driven by a desire to protect Ryota and prevent a "tragedy." Ryota's growing strength and unique abilities, particularly his S-rank drop stats and the ability to obtain items that raise stats, set him apart in this world. He also learns about the existence of "rogue monsters" that don't drop items but can yield powerful, world-specific items like his revolver. The narrative highlights the stark contrast between Ryota's past life of overwork and his current life of adventure and newfound purpose, all while navigating the peculiar rules and inhabitants of this new world.
