The Red Ranger, Tougo Asagaki, finds himself transported to another world in the middle of a fierce battle against forces of evil. Upon arriving, he quickly makes a name for himself as an adventurer and takes on a job from a young mage named Yihdra Arvoln. With his eccentric powers and frenzied personality, Tougo blazes through the mission with her. After the quest, Tougo and Yihdra begin adventuring together with their respective goals. Tougo strives to help as many as possible in the new world and find a way back home, while Yihdra desires to redeem her family lineage of mages and make magic accessible to everyone. Along their journey, the duo discover the limitations yet endless potential of the bonds they forge as they overcome adversities to achieve their aspirations.

At the beginning of chaos, the world was divided into three realms: the realm of deities, the realm of men, and the realm of demons. The realm of deities sent a spirit seed down into the world to help the common people. But the spirit seed continuously absorbed the evil of the world and cruelly harmed living things. In the end, Sen Luo, the king of the deities, sacrificed himself and sealed it. However, because of it, the Shangqing Xianmen, where the realm of deities is located, gradually waned and was lost in history. A thousand years later, the ruins of Shangqing Xianmen started to appear in succession. All major sects fought their hardest for possession of the treasures in the ruins.

Ever since the quiet and timid Reina Aharen enrolled in high school, she has made new friends and even started dating her classmate Raidou. When the two begin their second year, everything seems to be going well, as they are seatmates once more. Soon after, a transfer student named Riku Tamanaha joins their class. Unbeknownst to Reina, the outgoing and stylish girl is actually a childhood friend she separated from years ago. With Raidou's support, Reina is able to rekindle their friendship. Although they have grown closer, Raidou and Reina still struggle to communicate due to his overactive imagination and her difficulty with expressing herself. Nevertheless, the eccentric couple continues to brighten up the lives of people around them as they enjoy each other's company to the fullest.

Tsukasa Atsumi is a salaryman who leads an ordinary, solitary life. On his way back from work one evening, he is saved from a demon attack by a mysterious woman in a ninja outfit. Introducing herself as Shizuri Ideura, she claims that demons target people like Tsukasa, who have Samurai Blood in their veins, and that her kind have been protecting them from the shadows. Told by Shizuri that the attacks are going to become more frequent, Tsukasa makes a deal to provide her with housing in exchange for his safety. To his surprise, he quickly finds out that Shizuri is a shut-in who loves to play video games whenever she is not busy with her ninja duties. As the two spend more time together, Tsukasa grows to appreciate Shizuri's company—and his feelings just might be mutual.