Freed from the rule of samurai 150 years ago, the people of Hinomoto live peaceful lives and revere their liberators—demons whose true forms remain elusive—as gods. Fated to mine rocks for the demons to feast on, Musashi knows the grim truth: humanity is enslaved by these otherworldly beings and the samurai are the last bastion fighting for freedom. Hiding his true opinion from his peers and growing distant from his childhood friend Kojirou Kanemaki, Musashi lives in angst until the day of his graduation. When the fresh graduates arrive at the mine, they are horrified to see the inhumane treatment of miners and the uncanny physical appearance of their overseers. However, Musashi manages to endure thanks to Kojirou's help. As the demon leader wreaks havoc on the quarry, Musashi is saved once more from certain death by the Takeda samurai clan. Recovering from humiliation and yearning for adventure, Musashi embarks on a journey to become a samurai and form his own clan!

Ichirou Kuga has suddenly found himself taking on the responsibility of caring for his two younger siblings after their father's untimely death. To make ends meet, Ichirou rents out rooms in the apartment complex he inherited and works full-time as a shoujo manga artist. However, his manga sales are low, his assistants have recently left, and deadlines are fast approaching. As stress threatens to overtake Ichirou, salvation comes in the form of an extremely competent novice artist, Shiori Goshiki, who becomes his new assistant. With her skills, they are able to tide over the difficult situation, and things begin looking up. But in a bizarre accident, a supernatural experience unfolds between Ichirou and Shirou, which leads her to declare them engaged. With this seemingly innocuous action upending his life, Ichirou now has to manage his new and peculiar relationship with the mysterious girl, all the while following his own passion and fulfilling the duties that rest on his shoulders.

Shinichi Kanou is a shut-in otaku with a vast knowledge of anime, manga, and video games. One day, after applying for a job in hopes of escaping his secluded lifestyle, he is kidnapped and transported to the Eldant Empire—a fantasy world filled with elves, dragons, and dwarves. Trapped in this strange land, Shinichi is given an unlikely task by the Japanese government: to spread otaku culture across the realm by becoming an Otaku Missionary. To accomplish his mission, Shinichi has the full support of the Japanese government, as well as the half-elf maid Myucel and Princess Petralka of the Eldant Empire. Together with this ragtag bunch, he will overcome the obstacles of politics, social classes, and ethnic discrimination to promote the ways of the otaku in this holy land.

Zhuge Kongming earned a reputation as one of the greatest tacticians of the Three Kingdoms period of third-century China. Having led his army through countless grueling victories, Kongming falls gravely ill during the Battle of Wuzhang Plains. The weariness and regret stemming from the seemingly never-ending war catch up to him, and as he draws his final breath, Kongming wishes that if he were to reincarnate, he would be reborn in a more peaceful era. His wish comes true, and Kongming wakes up in modern-day Tokyo with a younger body and his memories intact. Thrust into an unfamiliar world, he finds his way into a nightclub and meets Eiko Tsukimi, an aspiring singer whose performance immediately captivates him. Pitying his confusion, Eiko takes Kongming under her wing and teaches him about the current world, which leads to Kongming's interest in contemporary music. Seeing Eiko's immense musical potential, Kongming vows to make the world recognize her and soon takes on the role of her manager. Unsurprisingly, the music industry is unforgiving to those who make even the slightest mistakes. Still, Kongming is determined to accomplish his goals—even if he must utilize the war stratagems he famously used in his previous life!