Five years ago, alien beings known as the Kiseichuu'' invaded the world. With the species endangered, the Kiseichuu are determined to take over Earth through a deadly plan that would gradually wipe out the human race: take away humanity's sexual drive using various methods, letting them die out. In response to the Kiseichuus' scheme, the HxEros device was developed—a powerful weapon that only those with high levels of erotic energy can utilize at its maximum capacity. Retto Enjou, a high schooler harboring an immense hatred toward the Kiseichuu, joins a group of HxEros users to fight against them and protect humankind. With their gear reliant on erotic energy as a source of power, the team must work together to maintain high levels of libido to ensure their readiness for combat at any given time. Moreover, as he lives in a house full of lustful girls, Enjou should not expect a shortage of power anytime soon.

Kyoto has been populated by groups of tanuki and tengu for years, living alongside humans who are oblivious to the existence of these creatures. Yasaburou Shimogamo is the third son of an influential tanuki family who spends his carefree days taking care of an old tengu, observing humans through his ability to shapeshift, and dealing with the mysterious woman named Benten. Behind the peace and tranquility, however, is a painful memory from long ago as Yasaburou's father, head of the tanuki community, was killed and eaten by a group of humans known as the Friday Fellows. Uchouten Kazoku follows the trials and tribulations of the Shimogamo brothers as they struggle to avoid their own grisly demise while coming ever closer to unraveling the truth behind their father's death.

With a dignified veteran's body and a long white beard, summoner mage Dunbalf was one of the strongest player characters in the virtual reality online multiplayer roleplaying game Ark Earth Online, even heralded as a one-man army. Together with the Nine Wise Mages and King Solomon, they formed the mage player Kingdom of Alcait. But one day, Dunbalf and the other Nine Wise Mages suddenly go missing, leaving no trace behind. In an effort to spend his expiring credits, Dunbalf had purchased a cosmetic kit and tinkered with his character; however, he accidentally fell asleep during the customization process. Upon waking up, Dunbalf not only notices that the world of Ark Earth Online has become more realistic, but also discovers that he has turned into a cute girl! After reaching Alcait, he learns it has been 30 years since he supposedly disappeared. Now tasked with finding the other missing mages by King Solomon, the avid role player proclaims his new identity as Mira—the Pupil of the Wise Man Dunbalf—and ventures forth to prove his legacy.

When aliens known as the Oni threaten to invade the Earth, they promise to leave under one condition—a randomly-chosen human must win a one-on-one game of tag against Lum, the beautiful daughter of the Oni leader. The lucky person selected happens to be the lustful and unlucky high schooler Ataru Moroboshi. Given 10 days to attempt to grab Lum's horns, Ataru realizes how impossible the challenge is as he is faced with Lum's extraterrestrial powers. Motivated by a promise of marriage from his childhood friend Shinobu Miyake, Ataru manages to catch Lum off guard. He mistakenly grabs hold of her bikini top first, but he eventually achieves his true goal. Although the game is over, Lum misunderstands that she is the one whom Ataru wants to marry, and she decides to move in with him. The poor student constantly tries to shake off the clingy Lum while doing his best to reconcile with his desired fiancée. After Ataru's heroic feat results in such a disastrous outcome, it is questionable whether luck will ever be on his side.