In the dawn of the 21st century, magic, long thought to be folklore and fairy tales, has become a systematized technology and is taught as a technical skill. In First High School, the institution for magicians, students are segregated into two groups based on their entrance exam scores: Blooms, those who receive high scores, are assigned to the First Course, while Weeds are reserve students assigned to the Second Course. Mahouka Koukou no Rettousei follows the siblings, Tatsuya and Miyuki Shiba, who are enrolled in First High School. Upon taking the exam, the prodigious Miyuki is placed in the First Course, while Tatsuya is relegated to the Second Course. Though his practical test scores and status as a Weed show him to be magically inept, he possesses extraordinary technical knowledge, physical combat capabilities, and unique magic techniques—making Tatsuya the irregular at a magical high school.

The aloof protagonist: a bookworm who is deeply detached from the world he resides in. He has no interest in others and is firmly convinced that nobody has any interest in him either. His story begins when he stumbles across a handwritten book, titled Living with Dying. He soon identifies it as a secret diary belonging to his popular, bubbly classmate Sakura Yamauchi. She then confides in him about the pancreatic disease she is suffering from and that her time left is finite. Only her family knows about her terminal illness; not even her best friends are aware. Despite this revelation, he shows zero sympathy for her plight, but caught in the waves of Sakura's persistent buoyancy, he eventually concedes to accompanying her for her remaining days. As the pair of polar opposites interact, their connection strengthens, interweaving through their choices made with each passing day. Her apparent nonchalance and unpredictability disrupts the protagonist's impassive flow of life, gradually opening his heart as he discovers and embraces the true meaning of living.

Thirty years ago, the Eurasian continent was devastated by a supermassive spatial quake—a phenomenon involving space vibrations of unknown origin—resulting in the deaths of over 150 million people. Since then, these quakes have been plaguing the world intermittently, albeit on a lighter scale. Shidou Itsuka is a seemingly average high school student who lives with his younger sister, Kotori. When an imminent spatial quake threatens the safety of Tengu City, he rushes to save her, only to be caught in the resulting eruption. He discovers a mysterious girl at its source, who is revealed to be a Spirit, an otherworldly entity whose appearance triggers a spatial quake. Soon after, he becomes embroiled in a skirmish between the girl and the Anti-Spirit Team, a ruthless strike force with the goal of annihilating Spirits. However, there is a third party that believes in saving the spirits: Ratatoskr, which surprisingly is commanded by Shidou's little sister! Kotori forcibly recruits Shidou after the clash, presenting to him an alternative method of dealing with the danger posed by the Spirits—make them fall in love with him. Now, the fate of the world rests on his dating prowess, as he seeks out Spirits in order to charm them.

After their triumphant victory over Shiratorizawa Academy, the Karasuno High School volleyball team has earned their long-awaited ticket to nationals. As preparations begin, genius setter Tobio Kageyama is invited to the All-Japan Youth Training Camp to play alongside fellow nationally recognized players. Meanwhile, Kei Tsukishima is invited to a special rookie training camp for first-years within the Miyagi Prefecture. Not receiving any invitations himself, the enthusiastic Shouyou Hinata feels left behind. However, Hinata does not back down. Transforming his frustration into self-motivation, he boldly decides to sneak himself into the same rookie training camp as Tsukishima. Even though Hinata only lands himself a job as the ball boy, he comes to see this as a golden opportunity. He begins to not only reflect on his skills as a volleyball player but also analyze the plethora of information available on the court and how he can apply it. As the much-anticipated national tournament approaches, the members of Karasuno's volleyball team attempt to overcome their weak points and refine their skills, all while aiming for the top!