Following the faceless god Hitogami's advice seems to have worked wonders for Rudeus Greyrat. After enrolling into the University of Magic as he was told, Rudeus reunites with his childhood friend Sylphiette, who put a valiant effort into curing his condition. The two grow ever closer together and decide to host a wedding party, inviting the friends they have made over the years to announce and formalize their relationship. For all his recent blessings, however, Rudeus' troubles are far from over. The research he is helping Shizuka Nanahoshi conduct hits a bottleneck, sending her into a deep slump much like he experienced in his previous life. Furthermore, a letter from his father, Paul, brings complications to Rudeus' relationships, and Sylphiette still knows next to nothing about his real background. In the face of these issues, Rudeus will have to apply the lessons he has learned in this new world to navigate through the challenges that come with living a life to its fullest.

Despite being bullied, scorned, and oppressed all of his life, a 34-year-old shut-in still found the resolve to attempt something heroic—only for it to end in a tragic accident. But in a twist of fate, he awakens in another world as Rudeus Greyrat, starting life again as a baby born to two loving parents. Preserving his memories and knowledge from his previous life, Rudeus quickly adapts to his new environment. With the mind of a grown adult, he starts to display magical talent that exceeds all expectations, honing his skill with the help of a mage named Roxy Migurdia. Rudeus learns swordplay from his father, Paul, and meets Sylphiette, a girl his age who quickly becomes his closest friend. As Rudeus' second chance at life begins, he tries to make the most of his new opportunity while conquering his traumatic past. And perhaps, one day, he may find the one thing he could not find in his old world—love.

After the mysterious mana calamity, Rudeus Greyrat and his fierce student Eris Boreas Greyrat are teleported to the Demon Continent. There, they team up with their newfound companion Ruijerd Supardia—the former leader of the Superd's Warrior group—to form "Dead End," a successful adventurer party. Making a name for themselves, the trio journeys across the continent to make their way back home to Fittoa. Following the advice he received from the faceless god Hitogami, Rudeus saves Kishirika Kishirisu, the Great Emperor of the Demon World, who rewards him by granting him a strange power. Now, as Rudeus masters the powerful ability that offers a number of new opportunities, it might prove to be more than what he bargained for when unexpected dangers threaten to hinder their travels.

In the immediate aftermath of the mana calamity, Sylphiette finds herself teleported to the heart of the Asura Kingdom: the royal palace. Her sudden appearance accidentally saves the life of second princess Ariel Anemoi Asura, who has her sights set on becoming the ruler of the realm. Witnessing Sylphiette's talent with combat magic firsthand, Ariel recruits her as her bodyguard and right-hand woman, commencing their journey to power—which proves far more treacherous than first imagined.