Chiyo Mihama begins her high school career as one of the strangest students in her freshman class—a tiny, 10-year-old academic prodigy with a fondness for plush dolls and homemade cooking. But her homeroom teacher, Yukari Tanizaki, is the kind of person who would hijack a student's bike to avoid being late, so "strange" is a relative word. There certainly isn't a shortage of peculiar girls in Yukari-sensei's homeroom class. Accompanying Chiyo are students like Tomo Takino, an energetic tomboy with more enthusiasm than brains; Koyomi Mizuhara, Tomo's best friend whose temper has a fuse shorter than Chiyo; and Sakaki, a tall, athletic beauty whose intimidating looks hide a gentle personality and a painful obsession with cats. In addition, transfer student Ayumu Kasuga, a girl with her head stuck in the clouds, fits right in with the rest of the girls—and she has a few interesting theories about Chiyo's pigtails! Together, this lovable group of girls experience the ups and downs of school life, their many adventures filled with constant laughter, surreal absurdity, and occasionally even touching commentary on the bittersweet, temporal nature of high school. [Written by MAL Rewrite]

Ousai Academy was originally an all-girls high school. Due to the declining birth rates in recent years, it was converted into a co-ed school. The first year male students would find themselves surrounded by girls and unfortunately, Tsuda Takatoshi is one of them. What's worse, he gets scolded on his first day by the student council president Shino Amakusa, which did not give a good first impression of him. Tsuda also meets the other student council members while getting scolded, and in the end, he gets late for class. As an apology for ruining his morning, Shino lets him join the student council for various of "reasons" and he accepts it, or rather, he's forced to accept. Thus begins his days as Tsuda soon realizes that he's the only normal student in Ousai Academy...

The cast is back and ready to quip! In this companion film that follows season 2 of the zany, irreverent Seitokai Yakuindomo anime series, the student council must again grapple with a mix of double-entendres and doubly potent teen hormones.

Founded in the Taisho era, the "Red Flower Opera Company" attracts people's hearts across generations on a beautiful and gorgeous stage created only by unmarried women. The 100th generation students who have passed through a high magnification and entered the "Red Flower Opera Music School" to develop the human resources. Sarasa Watanabe, an innocent girl with a height of 178 cm who longs for "Oscar-sama." Ai Narada, a former national idol who is indifferent to everything, both dreams and friends. The music school life full of hope and conflict, where everything is disjointed, is about to begin! (Source: MAL News)