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.

After witnessing his mother's death at a young age, Uryuu Kamihate grew up disillusioned with the gods, dismissing faith in them as utter nonsense. Due to his beliefs, he aims to become a doctor, spending most of his time studying to enter the prestigious Kyoto University. To further his studies, Uryuu searches for a new place to take him in and get away from the noisy environment of the orphanage where he grew up. Chidori Amagami, head priest of the Amagami Shrine, allows him to stay at the Amagami residence. However, Uryuu has to live there with Chidori's three granddaughters—Yae, Yuna, and Asahi—who serve as shrine maidens. Moreover, Chidori has another condition for Uryuu: he has to marry one of the sisters to ensure the shrine's future and one day inherit it. But with Uryuu's goals and outlook naturally clashing against the sisters' beliefs, this already daunting ordeal seems outright impossible.

High school student Haruka has always been a content loner. One day, he and his class are abruptly transported to another world and given skill points to use when choosing from an assortment of abilities and magical powers. Unfortunately, Haruka arrives last, and he can only use his points on the seemingly impractical abilities the others had no interest in. Although he is on his own again and must adjust to his new life by himself, he much prefers it that way. However, Haruka's peaceful solitude is short-lived, as he runs into some of his classmates. Weak to their pleas for help, he ends up sheltering and helping them reunite with the others. But the different cliques struggle to see eye to eye, forcing Haruka to find a way to end the infighting and restore harmony between them to survive the unfamiliar world.

After years of animosity, the leaders of Osaka's Somei and Tokyo's Miyama yakuza groups have called a truce—by arranging an engagement between their respective grandchildren, Yoshino Somei and Kirishima Miyama. To this end, 17-year-old Yoshino moves to Tokyo to live with the Miyama family and attend school with her new fiancé. Although Kirishima is all smiles and perfectly polite, there is something unsettling about his demeanor that Yoshino cannot put her finger on. Yoshino's suspicions are soon confirmed: despite his manners, Kirishima is a masochistic maniac. He hurts people without batting an eye and also revels in being punished verbally and physically himself. What he wants most is a spoiled and arrogant fiancée who will ruin his life. When Yoshino does not quite meet his expectations, he reveals his true colors and openly insults her. However, instead of running away in fear, Yoshino decides to take revenge by making Kirishima fall in love with her and then ruthlessly breaking his heart.