College student Yuuhi Amamiya's monotonous life is turned upside down with the appearance of Sir Noi Crezant, a talking lizard claiming to be a knight of justice. Crezant elaborates that the world is in peril—threatened by the mage Animus who wishes to annihilate it with his Biscuit Hammer, an enormous structure suspended in Earth's orbit. As the newly appointed Lizard Knight, Yuuhi must fight alongside other Beast Knights to protect the princess and save the planet from destruction. Unimpressed by the prospect of risking his life, Yuuhi continues his day as usual—until a golem created by Animus suddenly confronts him. Yuuhi is instantly overpowered, but his neighbor, Princess Samidare Asahina, luckily rescues him. To his surprise, Samidare's intention starkly differs from Crezant's; instead of saving the world, she aims to destroy it with her own hands. Captivated by her firm ambition, Yuuhi resolves to become stronger and help Samidare realize her goal. As the pair continues to fight against Animus' golems, Yuuhi finds himself gradually gaining an interest in life—but the chains of his past trauma may restrain him from progressing further.

After Musashi rescues Michiru Saruwatari from a demon, his friend Kojirou Kanemaki discovers that his father was a member of the Uesugi clan. Determined to learn more about his own past, Kojirou—alongside his Kanemaki clansmen—decides to participate in Uesugi's punitive expedition against the demon lord of Awajima Island: Yamata no Orochi, an eight-headed dragon that threatens to engulf the entire region. However, upon joining Uesugi's military alliance, Musashi faces the harsh reality of fighting against powerful demons. Humiliated by his lack of power and inability to work in groups, he has to learn how to cooperate with his newfound allies. Meanwhile, the Obsidian Eight—a group pursuing the Obsidian Goddess that dwells within Musashi's body—resumes its hunt for Musashi, and plans to thwart the ongoing island operation. As the situation grows chaotic, Musashi and his friends must foil the machinations of the various factions conspiring to seize the Obsidian Goddess.

To prepare for reincarnation in another world, Kelvin gives up select memories from his previous life in exchange for powerful abilities, additional skill points, and an S-class summoner title. As a bonus, the goddess facilitating his rebirth, Melfina, offers him a choice of any companion to give him a head start in his summoner role. Kelvin—who has fallen head over heels for Melfina at first sight—promptly chooses the deity, confident that his passionate feelings for her will resurface even without all of his memories. Kelvin embarks on his exciting new journey with Melfina as his guide. However, in order to summon his beloved goddess' physical form, he needs to acquire significant amounts of mana points—and the best way to accomplish this is to level up by fighting strong enemies and making contracts with even stronger companions.

World-class medical researcher Kanji Yakutani lost his little sister to a tumor years ago due to ineffective treatment. To honor her legacy, he has dedicated his research to developing new medications for such conditions. But as fate would have it, he overworks himself and passes away at the age of 31, only to be given a second chance at life in another world. When he wakes up, Kanji finds himself in the body of a 10-year-old boy named Falma de Médicis, the son of an esteemed family of medical practitioners in the Sain Fleuve Empire. Bearing the mark of a deity's divine blessing, Falma is capable of performing a unique divine art, allowing him to create and reduce any substance with the knowledge of its chemical properties. After reading through some pharmacology books, Falma realizes that this world is operating on similar medical practices as in ancient times. He also learns that medicine is an exclusive privilege to the nobility, depriving commoners of proper medical care. Using the knowledge from his past life and the divine abilities granted to him, Falma resolves to make medicine available to those who need it—irrespective of class.