Asa and Kame strike up an immediate friendship when they arrive at the same time for their first day of duty at the Ooku, the splendid pleasure palace housing the harem of Lord Tenshi. The two young women are there to join the many hundreds of other maidservants—men are barred from entering, with immediate beheading the price of trespassing. It soon becomes clear that behind the luxurious lifestyle and ritualized routines of the Ooku lie sinister schemes and cynical rivalries. Meanwhile, a mysterious wandering potion-peddler known only as the Medicine Seller subtly insinuates himself into the Ooku, just as an uncanny, otherworldly menace begins to reveal itself. (Source: Fantasia Festival)

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 the events of the 1st series, Fenarinarsa continues to drift from Earth, so the King asks for help from the kingdom, Marinarsa, to send their daughter, Momo (Who is identical to the 1st one) to Earth to regain humanity's faith in their dreams.

Despite not understanding much about fleeting teen romance, first-year high school student Kazuhiko Nukumizu still wonders how he would react if his life were to be turned into a love story. Regardless, as a self-proclaimed background character, Nukumizu is satisfied continuing his life as an introvert with a negligible social life. However, he suddenly finds himself too close to the spotlight when he witnesses his popular classmate Anna Yanami be rejected by her childhood friend in the middle of a family restaurant. While Nukumizu wishes he could just forget what he saw and move on, Anna ends up forcefully confiding herself in Nukumizu, lamenting her status as a childhood friend fated to have her beloved stolen. As he becomes dragged into Anna's situation, Nukumizu soon gets caught up in the relationship drama of two more girls: Lemon Yakishio, an outgoing member of the track and field club; and Chika Komari, a shy member of the literature club. Now thrust out of his comfort zone, Nukumizu finds himself a major character in the lives of too many losing heroines.