Misaki Ayuzawa is a unique phenomenon within Seika High School. In a predominantly male institution, she became the first-ever female student council president through her honesty and diligence. Ever since Misaki got promoted to the position, she has been working tirelessly to ensure a better school life for all girls. Despite that, Misaki is very strict with the boys, which has earned her the title Demon President. One day, after hearing a girl cry in the hallway, Misaki encounters Takumi Usui—the most popular boy in the school—as he rejects a love confession. Enraged at what she is seeing, Misaki reprimands him for making the girl cry. However, Usui is indifferent and brushes it off as nothing. Unexpectedly, Misaki soon runs into Usui again, but this time when she is working at a maid cafe! Embarrassed that someone has found out about her secret occupation, Misaki promises herself not to let Usui destroy her reputation. However, the mysterious boy now begins to visit the same cafe regularly to observe and tease Misaki. When push comes to shove, will Usui still be able to keep the president's secret?

Koyomi Araragi, a third-year high school student, manages to survive a vampire attack with the help of Meme Oshino, a strange man residing in an abandoned building. Though being saved from vampirism and now a human again, several side effects such as superhuman healing abilities and enhanced vision still remain. Regardless, Araragi tries to live the life of a normal student, with the help of his friend and the class president, Tsubasa Hanekawa. When fellow classmate Hitagi Senjougahara falls down the stairs and is caught by Araragi, the boy realizes that the girl is unnaturally weightless. Despite Senjougahara's protests, Araragi insists he help her, deciding to enlist the aid of Oshino, the very man who had once helped him with his own predicament. Through several tales involving demons and gods, Bakemonogatari follows Araragi as he attempts to help those who suffer from supernatural maladies.

For weeks, Atsushi Nakajima's orphanage has been plagued by a mystical tiger that only he seems to be unaware of. Suspected to be behind the strange incidents, the 18-year-old is abruptly kicked out of the orphanage and left hungry, homeless, and wandering through the city. While starving on a riverbank, Atsushi saves a rather eccentric man named Osamu Dazai from drowning. Whimsical suicide enthusiast and supernatural detective, Dazai has been investigating the same tiger that has been terrorizing the boy. Together with Dazai's partner Doppo Kunikida, they solve the mystery, but its resolution leaves Atsushi in a tight spot. As various odd events take place, Atsushi is coerced into joining their firm of supernatural investigators, taking on unusual cases the police cannot handle, alongside his numerous enigmatic co-workers.

At Suimei High, the Sakura-sou dormitory is infamous for housing the school's most notorious delinquents. Thus, when the relatively tame Sorata Kanda is transferred to the dorm, escaping this insane asylum becomes his foremost goal. Trapped there for the time being, he must learn how to deal with his fellow residents, including bubbly animator Misaki Kamiigusa, charming playboy writer Jin Mitaka, and the ever-reclusive Ryuunosuke Akasaka. Surrounded by weirdness, Sorata frequently finds respite in his interactions with his one normal friend, aspiring voice actress Nanami Aoyama. When Mashiro Shiina—a new foreign exchange student—joins the dormitory, Sorata is instantly enraptured by her beauty. Underneath her otherworldly appearance, Mashiro is an autistic savant, capable of world-renowned brilliance in her art, yet unable to perform simple daily tasks. After Sorata ends up in charge of taking care of Mashiro, the two inevitably grow closer, with Sorata's initial desire to escape the dormitory becoming a forgotten goal. Despite their eccentricities, every resident is incredible in their own field, leaving Sorata to contend with his own lack of any particular skill. With brilliance all around him, he thus strives to become an equal to their talent. Revolving around the hardships and joys of its colorful cast, Sakura-sou no Pet na Kanojo is a heartwarming coming-of-age tale of friendship, love, ambition, and heartbreak—through the lens of an ordinary person surrounded by the extraordinary.