The story begins with Yuu, a sixth-grader with stunted growth due to an accident, being introduced to the highly anticipated VRMMO game, "Fantasy World Online" (FWO), by his close friend Takumu. Takumu, who won a beta tester lottery, offers Yuu his spare copy, allowing Yuu to start playing immediately. Yuu, initially hesitant due to his lack of gaming experience and the game's popularity, eventually accepts.
Upon logging in, Yuu finds himself in the character creation room. He opts for a human race and chooses the "Summoner" class, a rare and unconventional choice that surprises his friends. He also customizes his appearance, making it similar to his real-life self, with long black hair.
Yuu's first in-game experience is overwhelming due to the sheer number of players. He is quickly reunited with Takumu, who has equipped himself with impressive gear, including "Hover Boots." Takumu is accompanied by Yuu's younger sister, Tsubasa, who is playing as "Sylph," an Elf Fighter with powerful beta tester gear. To Yuu's shock, his avatar appears as a young girl, a fact that his sister and Takumu find amusing, while Yuu insists he is male.
Sylph explains that beta testers receive half of their in-game assets and money from the beta test, explaining their superior equipment. Yuu, as a Summoner, faces immediate challenges. His chosen class is revealed to be a "minefield" job due to its reliance on sealing monsters for summoning, which prevents item drops, and the difficulty of reaching the maximum summon limit. His primary weapon, a book, is also considered impractical for early-game combat.
Despite these disadvantages, Yuu, with the help of Takumu and Sylph, begins his journey. They hunt rabbits to seal them and increase Yuu's summoning capabilities. Yuu also learns about the game's mechanics, including skills and stat allocation. He chooses to prioritize agility, and his summoned rabbit, named "Boparu," also levels up.
Their exploration leads them to a forest where they encounter various monsters. Yuu attempts to use fire magic but finds it impractical. Boparu proves to be a valuable companion, with excellent scouting abilities and combat prowess, even defeating a caterpillar monster on its own.
Later, while hunting wild dogs, Yuu and Boparu face a dangerous situation. Takumu and Sylph, having defeated their own targets, observe rather than assist, leading to Yuu's frustration. However, Yuu and Boparu manage to defeat the wild dogs through effective teamwork, with Boparu acting as a crucial distraction and Yuu delivering the finishing blows.
After this battle, they return to town and meet with Ria, a merchant and leader of a production-class alliance, and Ren, a skilled woodworker who crafts weapons. Yuu receives a "Kashi Rod" from Ren as a gift, as his Summoner class makes it difficult to earn money early on.
The story concludes with Yuu, Boparu, and his friends venturing deeper into the forest. They encounter a mysterious girl dressed as a magical girl, who is being attacked by a swarm of crows. Yuu and Boparu intervene, and Yuu engages in a difficult battle against the crows, showcasing his growing combat skills and determination to protect his summoned companion.
