Despite having a good reputation as one of the most seasoned guards in the local guild of Mebuki, Kikuru Madan believes he has been wasting his youth and hopes to spend the rest of it like any other person. However, his conscience prevents him from retiring at present, as he worries about the guild's future without him. Coincidentally—as if to help him find his successor—the guild's receptionist, Enome, assigns Kikuru four fresh recruits: the energetic beastwoman Hitamu "Hitamuki" Kyan, the prodigy Maidena Ange, the laid-back Toxico Dannar, and the stalwart Hanabata Nohkins. Although each of them possesses significant talents, they also display characteristics that detract from their potential—including Hitamu's extreme clumsiness and Hanabata's unintentional perverseness. As if there was not enough to deal with, the monsters outside Mebuki's walls start exhibiting odd behavior by targeting women salaciously, causing the party endless problems in more ways than one. Nevertheless, Kikuru is committed to retiring early; to achieve his goal, the guidance he gives the trainees will be absolutely essential.

In the near future when technology has significantly advanced, a famous AI TV fortune teller seemingly foresees high school student Asahi Kashiwagi's day with pinpoint accuracy. On his way to school, he encounters Aoi Izumisawa, Bai Mongfa, Karin Istel, Amelia Irving, and Ilya Ilyukhin. Despite meeting them for the first time, Asahi suddenly receives love confessions from all of them at the end of the same day, perfectly aligning with the fortune teller's prediction. As if that was not enough, Asahi soon learns that these five individuals are actually candidates to become his bride, and they have been invited by his father to live at Asahi's home. Left with no other choice, he reluctantly allows them to stay, resulting in a bawdy turn of events that brightens up his average high school life. However, as Asahi spends more time with them, forgotten memories gradually resurface. While uncovering the hidden truth, Asahi begins to believe that his fate with these potential partners might be more than just mere coincidence.

Despite their distinctive personalities, Souma Shiki, Hayate Ichikura, Shun Futami, and Takayuki Mima all have one thing in common: though naturally clumsy, the four disguise their embarrassment from tiny slip-ups by maintaining a composed demeanor. However, it is actually the guys' airheaded natures that makes the girls' hearts throb. No matter what happens in their daily lives, the boys do their best not to lose their cool!

Suletta Mercury leaves her planet and enters the Asticassia School of Technology at the behest of her mother. There, right and wrong are determined through duels between students, and the top-ranking duelist will receive Miorine Rembran as their fiancée—this prize being decided by Miorine's father. When Guel Jeturk, the best pilot in school and Miorine's current fiancé, demands that his betrothed move in with him, Suletta disapproves, so Guel challenges her. Although she emerges as champion, Suletta is subsequently detained on suspicion of piloting a forbidden type of mobile suit—a GUND-ARM, or "Gundam"—which results in her victory being voided. Miorine refuses to accept any more injustices and proposes another duel with even higher stakes. Now, Suletta must triumph a second time, otherwise she will be expelled and the Gundam Aerial that means so much to her will be destroyed.