In the year 2043, , the world's first successful full-dive VRMMO was released. In addition to its ability to perfectly simulate the five senses, along with its many other amazing features, the game promised to offer players a world full of infinite possibilities. Nearly two years later, soon-to-be college freshman, Reiji Mukudori, is finally able to buy a copy of the game and start playing. With some help from his experienced older brother, Shuu, and his partner Embryo, Reiji embarks on an adventure into the world of . Just what will he discover and encounter in this game world known for its incredible realism and infinite possibilities?

Some urban legends are best left untested! Yuuto Suou gets more than he bargained for when he joins his childhood friend Mitsuki Shimoya in testing out an urban legend. When he uses his phone to take a picture of himself with the local shrine's divine mirror, he is whisked off into another world—one heavily steeped in the lore of the old Norse myths. Using his knowledge gained from school and from his solar-powered smartphone, he has the chance to bring the Wolf Clan, the same people who cared for him, to prominence, all while earning the adoration of a group of magic-wielding warrior maidens known as the Einherjar.

In the kingdom of Earlshide, Merlin Walford was once regarded as a national hero, hailed for both his power and achievements. Preferring a quiet life however, he secludes himself deep in the rural woods, dedicating his time to raising an orphan that he saved. This orphan is Shin, a normal salaryman in modern-day Japan who was reincarnated into Merlin's world while still retaining his past memories. As the years pass, Shin displays unparalleled talent in both magic casting and martial arts, much to Merlin's constant amazement. On his 15th birthday however, it becomes apparent that Shin only developed his combat skills and nothing else, leaving him with blatant social awkwardness, a lack of common sense, and a middling sense of responsibility. As a result, Shin enrolls in the kingdom's Magic Academy to hone his skills and mature among other teenagers. However, living a normal life is impossible, as he is established as a local celebrity almost as soon as he arrives. Kenja no Mago follows Shin Walford's high school life in the capital as he makes new friends, learns about the world, and fights off the various forces of evil surrounding him and his city.

Akira Oono is an ordinary working adult who manages the MMORPG Infinity Game. Fifteen years after creating the game, Oono decides to shut the servers down once and for all. However, as the clock strikes midnight, he somehow finds himself in the body of middle-aged Hakuto Kunai, Infinity Game's Demon Lord! Soon after his mysterious transportation, he witnesses the demon Greole chasing after a little girl named Aku. Although he effortlessly dispatches the creature, Hakuto is still concerned; after all, he does not remember creating the girl or the demon! Doubting whether he truly is in the world of his creation, Hakuto decides to investigate. Bringing Aku along as his guide and companion, Hakuto sets out on a journey to find out exactly who or what summoned him to this fantasy world—all while leaving chaos and destruction in his wake.