Powerful, avaricious sorceress Lina Inverse travels around the world, stealing treasures from bandits who cross her path. Her latest victims, a band of thieves, wait in ambush in a forest, thirsting for revenge. When Lina is about to effortlessly pummel her would-be attackers, the swordsman Gourry Gabriev suddenly announces his presence. Assuming Lina to be a damsel in distress, the foolish yet magnanimous man confronts the brigands in order to rescue her. After defeating them posthaste, the oblivious cavalier decides to escort Lina to Atlas City. Though not very keen on this idea, she ends up accepting his offer. However, without realizing it, Lina has chanced upon a mighty magical item among her most recent spoils. Now two mysterious men are hunting the young magician and her self-proclaimed guardian to obtain this powerful object for apparently nefarious purposes. This way they begin their adventure, one where the fate of the world itself may be at stake.

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.

Average student Mitsuki Mutou suddenly finds himself transported to another realm. Summoned by the king of this world for the remarkable power he is supposed to possess, Mitsuki is thrown out when it appears that he lacks a Special Concept. Moping about, he encounters a priestess named Menou who explains that Japanese people like him are known as Lost Ones, and such individuals never fail to have Special Concepts. Menou elaborates that she is part of a church that helps abandoned Lost Ones integrate into society. She invites him to spend the night at her church, where the two can probe the nature of his ability. Eventually, they discover that Mitsuki's Special Concept is actually incredibly powerful and dangerous. But is Menou's true goal to assist Lost Ones—or the opposite?

Touya Mochizuki grows accustomed to his new life in another world. Armed with his trusty smartphone, the teenager accepts small quests at his leisure while spending time with his new fiancées: Yumina Urnea Belfast, Yae Kokonoe, and twin sisters Linse and Elze Shileska. But even in a relaxing environment, Touya is only beginning to understand the responsibilities that come with these engagements. In addition to his romantic woes, the elder fairy Lean wishes to locate the remaining pieces of Babylon, the floating island that the mysterious Professor Regina Babylon created five thousand years ago. Touya reluctantly accepts her request and seeks out the teleportation circles that will lead to the islands. However, strange monsters have emerged—possibly powerful enough to destroy the world. In order to save the second life he was given, Touya must weaponize ancient technologies to fight these monsters—all while balancing his overwhelming number of relationships.