After his grandmother Sachiko passes away, Hayato Kasukabe returns from Tokyo and inherits her cafe—Familia Café Terrace. He aims to demolish the cafe and convert it into a parking lot, only to discover that his grandmother had taken in five girls prior to her death. The girls—Ouka Makuzawa, Akane Hououji, Riho Tsukishima, Shiragiku Ono, and Ami Tsuruga—evidently shared a deep bond with Sachiko, and they naturally refuse to give up the place they call home. They convince Hayato to change his mind, albeit reluctantly. Through this encounter, Hayato eventually remembers his past with his grandmother as well as his love for the cafe. Now resolved to carry on his grandmother's legacy, Hayato enlists the girls to act as the goddesses that will ensure the preservation of this precious abode.

During their martial arts training expedition in China, Ranma Saotome and his father Genma suffered an accident, which in turn, afflicted them with a curse—whenever they are doused with cold water, Ranma transforms into a girl, while his father turns into a panda! Only hot water can reverse these changes, but any further contact with cold water opens the can of worms once more. Unfortunately, the trouble does not end there, as Ranma finds out about his betrothal to one of the daughters of Soun Tendou, his father's closest friend. During the families' first meeting, it is decided that Ranma is to be married to Akane, the youngest daughter, a decision that is met with vehement protests from both sides. The two are simply not compatible, yet they are forced to live under one roof. Ranma's status quo further adds to the chaos, leading him to a series of comedic situations and misunderstandings that, in the grand scheme of things, may just be what he needs to work with Akane.

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.

Aspiring light novel author Yuu Nagami regularly enters writing competitions but has yet to win a single one. Despite his recurring failures, he remains steadfast in his resolve to become a better writer. When he takes a look at the list of winning authors in the latest contest he joined, he notices that someone named Chikai Towano dominated the competition. He soon discovers that behind the pen name is his sister Suzuka—the last person he can imagine being an author. Suzuka cannot reveal to anyone that she is Chikai Towano and requests her brother to take her place. Yuu agrees with one condition: he will continue posing as Chikai Towano for his sister until he publishes his own book. Until that happens, Yuu uses his new identity as an opportunity to improve his writing skills and meet fellow authors and new acquaintances along the way.