Since childhood, Aoba Suzukaze has loved the Fairies Story game series, particularly the character designs. So when she graduates from high school, it is no surprise that she applies to work at Eagle Jump, the company responsible for making her favorite video game. On her first day, she is excited to learn that she will be working on a new installment to the series: Fairies Story 3—and even more so under Kou Yagami, the lead character designer. In their department are people who share the same passion for games. There is Yun Iijima, whose specialty is designing monsters; the shy Hifumi Takimoto, who prefers to communicate through instant messaging; Hajime Shinoda, an animation team member with an impressive figurine collection; Rin Tooyama, the orderly art director; Shizuku Hazuki, the game director who brings her cat to work; and Umiko Ahagon, the short-tempered head programmer. New Game! follows Aoba and the others on their adventure through the ups and downs of game making, from making the perfect character design to fixing all the errors that will inevitably accumulate in the process.

Veteran adventurer Nick, mage Tiana, cleric Zem, and half-dragon Curran each show up alone at a tavern, only to find themselves seated at the same table. As the night goes on, they take turns divulging their grievances and the hobbies they have taken up as a means of coping. While their stories are utterly different, there is one common thread: betrayal. Each of the four, having been bitterly betrayed by someone they treasured, has developed a deep-seated distrust of humanity. But in addition to their similar worldviews, the four have one more commonality: a critical lack of funds. Realizing that things cannot continue as they are, they decide to form a party, rank up, and make as much money as possible to spend on their respective hobbies. What these disillusioned adventurers do not know, however, is that they will one day save the world from unfathomable peril.

In ancient Disboard, Riku is an angry, young warrior intent on saving humanity from the warring Exceed, the 16 sentient species, fighting to establish the One True God among the Old Deus. In a lawless land, humanity's lack of magic and weak bodies have made them easy targets for the other Exceed, leaving the humans on the brink of extinction. One day, however, hope returns to humanity when Riku finds a powerful female Ex-Machina, whom he names Schwi, in an abandoned elf city. Exiled from her Cluster because of her research into human emotions, Schwi is convinced that humanity has only survived due to the power of these feelings and is determined to understand the human heart. Forming an unlikely partnership in the midst of the overwhelming chaos, Riku and Schwi must now find the answers to their individual shortcomings in each other, and discover for themselves what it truly means to be human as they fight for their lives together against all odds. Each with a powerful new ally in tow, it is now up to them to prevent the extinction of the human race and establish peace throughout Disboard.

Sixteen sentient races inhabit Disboard, a world overseen by Tet, the One True God. The lowest of the sixteen—Imanity—consists of humans, a race with no affinity for magic. In a place where everything is decided through simple games, humankind seems to have no way out of their predicament—but the arrival of two outsiders poses a change. On Earth, stepsiblings Sora and Shiro are two inseparable shut-ins who dominate various online games under the username Blank. While notorious on the internet, the pair believe that life is merely another dull game. However, after responding to a message from an unknown user, they are suddenly transported to Disboard. The mysterious sender turns out to be Tet, who informs them about the world's absolute rules. After Tet leaves, Sora and Shiro begin their search for more information and a place to stay, taking them to Elkia—Imanity's only remaining kingdom. There, the duo encounters Stephanie Dola, an emotional girl vying for the kingdom's sovereignty. In desperation, she attempts to regain her father's throne, but her foolhardiness makes her goal unachievable. Inspired by the girl's motivation and passion, Sora and Shiro decide to aid Stephanie in getting Elkia back on its feet, ultimately aiming to become the new rulers of the enigmatic realm.