Though he grew up as an orphan, Nio Chirinu finds a place to belong: being a waiter at his adoptive grandmother's restaurant. But this peace does not last long; Nio and his sister Iroha are used as bait to arrest child abductors by Toshizou Hijikata and Souji Okita—two members of an infamous ronin group called Miburo. After the ordeal, Toshizou proposes that Nio join the ranks of Miburo and protect the people of Kyoto. Frustrated by his own weakness, Nio trains to match the swordsmanship of his new comrades. Even so, he struggles to be accepted by Tarou Tanaka and Hajime Saitou, the other Miburo members of his age. Determined to befriend them, Nio must discover his own sense of justice and become strong enough to prevail against all his enemies.

Following a bad experience teaching at a public high school that resulted in a break from working, Haruaki Abe eagerly takes up a new job at Hyakki Academy. Despite his cowardice, the novice teacher is motivated to do better this time around. However, his mind quickly changes when he finds out that everyone at the school is actually a supernatural being known as a youkai, leaving him glaringly out of place as the only human around. Facing his class as its new homeroom teacher, Abe immediately becomes a target for the students' antics due to his quick-to-scare nature. Though as the man starts to learn more about the creatures, as well as himself, getting along with the unruly group might not be as hard as he originally thought as their school lives begin to get more vibrant.

En route to conquer a Great Labyrinth with his allies and former classmates, Hajime Nagumo is sidetracked by a tragedy that befalls his party member Shea Haulia. After encountering a group of rabbitmen caught in an ambush, Nagumo learns that members of Shea's Haulia Tribe have been abducted by soldiers of the Hoelscher Empire. To alleviate the anxiety of Shea, whose father may be in mortal danger, Nagumo decides to head toward the empire and rescue the missing Haulias. After arriving at his destination, Hajime is caught up in political turmoil between the empire and the Heiligh Kingdom. As princess Liliana S. B. Heiligh tries to formalize an alliance with the empire to protect her weakened kingdom against demon attacks, the Haulia Tribe plans to assassinate Emperor Gahard D. Hoelscher to free all rabbitmen from the empire's threat. Determined to protect his allies at any cost, Hajime will need to ignore all political considerations and unleash his unstoppable power on anyone who may stand in his way.

Five hundred years ago, the fantasy world of Alneath was torn apart by a war between magically gifted immortals and mortals armed with magical artifacts. The conflict came to an end when mortals' hero, Gram, slayed the Demon Lord Veltol Velvet Velsvolt. In 2099, the world looks a bit different. Alneath and technologically advanced Earth have fused in an event known as Fantasion. Immortals have been hunted down to near extinction, and technological implants called Familia allow mortals to use magic. As the new world slowly recovers, Veltol's vassal Machina Solege resurrects him in Shinjuku, a techno-magical city constructed in the middle of devastated lands. However, Veltol's magic is severely weakened, and his former ally Marcus has betrayed him. To regain his fame and magical abilities, Veltol follows the advice of Takahashi—Machina's friend and a professional hacker—to start an unusual career: live streaming. His sharp tongue and comically poor gaming skills quickly secure him followers, but to dominate the world once again, Veltol must first uncover Shinjuku's secrets and thwart Marcus' vile plans.