As his school days draw to an end, Yuuki Wakura worries about his future. While lamenting the prospect of living an ordinary life, he is suddenly drawn into the world of Mato: an alternate dimension filled with dangerous monsters called Shuuki. Over the years since the existence of Mato was first confirmed, incidents of people accidentally wandering into the other world have become commonplace. To combat the threat of the Shuuki and rescue victims like Yuuki, the all-female Demon Defense Force was established. Its members have been blessed with the power of Peaches—Mato fruits that grant supernatural abilities only to women. Though Yuuki's situation is dire, he is saved in the nick of time by Kyouka Uzen, the chief of the Demon Defense Force's seventh unit. Despite Kyouka's impeccable skills in battle, she has long been held back by her Peach-granted ability, Slave. Slave allows Kyouka to put a living being under her control and draw out its strength, but the Shuuki that she had enslaved until now had all proven to be exceedingly weak. When Yuuki and Kyouka become surrounded by a horde of Shuuki, Kyouka resorts to something she has never tried before: using her ability on a man. To her surprise, Yuuki's slave form is much more powerful than she could have imagined. Believing the young man to be the key to unlocking her true potential, Kyouka invites Yuuki to join the Demon Defense Force—but not as a regular member.

When loner Touka Mimori is summoned to another world alongside his classmates, he obtains the power to inflict status ailments, such as paralysis or poison, on his enemies. Unfortunately for him, skills of this nature are considered useless due to their low success rate, and Touka is thus assigned the title of E-rank hero. Things take a further turn for the worse when Vicius, the goddess who summoned the class, reveals that the lowest-ranked hero will be disposed of so that they do not hinder those with greater talent. Banished to a notoriously dangerous area, Touka comes face-to-face with death after being cornered by a minotaur-like creature. In a desperate attempt to survive, he uses his supposedly worthless skill—only to quickly realize that it works almost every time. Armed with the ability to render the monsters standing in his way completely helpless, Touka resolves to track down the goddess that tossed him aside and exact his revenge.

In the 16th century, the city of Florence booms with cultural and creative revival in celebration of the Renaissance. Arte, a delightful young lady from an aristocratic family, dreams of being an artist and contributing to the renewal of civilization. However, with her father's death, she ends up losing the only person who believed in her passion for art. Now she is expected to marry a nobleman and live as a refined housewife without disgracing her family name. Reluctant to accept her fate, the headstrong Arte steps into the streets in search of a master artisan to take her on as an apprentice. In her quest for a mentor, Arte has to face harsh reality when she is completely shunned for being a female artist. No one believes that women are capable of fine craftsmanship, and therefore none are willing to accept her. Luckily, a renowned artisan by the name of Leo is persuaded to take her as his disciple since he has none anyway. And thus, Arte's new life begins, far from the comfort of her noble upbringing. As an apprentice, she must earn her keep while tackling various challenges along the difficult path to becoming a full-fledged, master artisan.

Following the first season, Tomoharu is now faced with a dilemma: if he doesn't form a contract with an akuma, he risks losing his dear friend Takatsuki. However, doing so would compromise his own existence as it would result in him and his ghost friend Misao becoming an Asura Cryin'—mankind's biggest threat, according to their school's presidents. To make the decision even harder, Tomoharu and Misao have recovered some of their past memories—memories of a world that they didn't even know existed.