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.

For generations, the Bernstein family has been recognized as a house of nobles who favor books over everything else. Elianna Bernstein, daughter of a baron of the Sauslind Kingdom, is no different. But instead of being called a bookworm, she is known as the Bibliophile Princess. Four years ago, the crown prince, Christopher Selkirk Asherald, offered Elianna a special arrangement: if she would become his fiancée, he promised that she could continue to spend all her free time reading. Despite having to inherit a title of great responsibility, she agreed to the proposal, enticed by the prospect of gaining access to the royal archives housing a wide selection of books. To this day, Elianna firmly believes that her engagement is void of romantic sentiment. When she notices Christopher's interactions with another girl, she presumes that the days she spends with him will soon reach an end. Yet, during this period of uncertainty, Elianna and Christopher open a new chapter in their relationship, gradually uncovering their genuine feelings as they grow to better understand each other.