Teacher Nano Saikawa hasn't given much thought to marriage, but her father's friend wants her to have a marriage interview with his son, Souichirou Takamiya. After the interview, they spend the day together. As they gradually become more comfortable with one another, Souichirou asks for her hand in marriage. Things quickly heat up between them, and the two wind up in bed together. However, when she removes his glasses, she discovers he is not Souichirou; he is actually one of her problem students, Souji Kuga! Souji's explanation is watertight: when he realized his brother was to be Nano's intended, Souji posed as him in order to be with her. And what's more, he is even confident that his family will approve of their marriage. However, an illicit relationship with a student is the last thing Nano wants. But will she be able to resist his charms, especially when her body begins to ache for his?

The story begins with Izumi Hayato running to be student council president. But when a beautiful girl swings in promising the liberalization of love while flinging condoms into the audience, he ends up losing to her and becoming the vice president. At the student council meeting, the newly-elected president invites herself over to Izumi's house, where she promptly announces she is to become Izumi's wife thanks to an agreement—facilitated by alcohol—made between their parents when they were only 3. (Source: MAL Scanlations)

After the death of his parents, Yuuto Amakawa lives a pretty ordinary life in the city. The only problem he has to worry about while attending school alongside Rinko, his next-door neighbor, is his cat allergies. That all changes on his sixteenth birthday, when an Ayakashi—a supernatural creature—attacks him for the sins of his ancestors. Luckily, he is saved by Himari, a mysterious cat-woman with a sword, who explains that Yuuto is the scion of a family of demon-slayers, and she is there to protect him now that the charm that kept him hidden from the supernatural forces of the world has lost its power. Omamori Himari chronicles Yuuto's dealings with the various forces of the supernatural world, as well as the growing number of women that show up on his doorstep, each with their own dark desires. Will Yuuto be able to adjust to his new exciting environment? Or will the ghost of his (ancestor's) past catch up with him?

Nori Kamitsuki has recently moved to the Gunma prefecture from Chiba, following after Otoya Todoroki, a former friend who moved there in elementary school. While on the way there, he receives an ominous text message from Todoroki telling him to turn back and that once someone enters Gunma, they never return. Ignoring the message, As Kamitsuki goes about his school life and makes new friends. These people make it their mission to prove any negative stereotypes surrounding Gunma wrong and show Kamitsuki all the ways Gunma is different from the rest of Japan—from its local foods and landmarks, the changes to its daily school life, and even the attitude of the people who live there. Gunma is widely regarded as the least popular prefecture in Japan, but they clearly don't know Gunma yet!