"School Days" is a 12-episode anime series based on a visual novel by 0verflow. The story centers around Makoto Itou, a high school student who becomes entangled in a complex web of romantic relationships. At the start, Makoto develops a crush on Kotonoha Katsura, a shy and reserved classmate. Encouraged by his friend Sekai Saionji, Makoto begins to pursue Kotonoha, and the two eventually start dating. However, Sekai, who harbors her own feelings for Makoto, becomes increasingly involved in their relationship, leading to a love triangle.

As the series progresses, Makoto's indecisiveness and lack of emotional maturity cause the situation to spiral out of control. He begins to engage in relationships with multiple girls, including Sekai, Kotonoha, and others, such as Hikari Kuroda and Otome Katou. This behavior creates tension and jealousy among the characters, particularly between Sekai and Kotonoha, who both vie for Makoto's affection. The relationships grow increasingly toxic, with manipulation, betrayal, and emotional turmoil becoming central themes.

The narrative takes a darker turn as the characters' actions escalate. Sekai, feeling abandoned and hurt by Makoto's actions, becomes emotionally unstable. Kotonoha, once gentle and kind, begins to exhibit signs of obsession and desperation. The series culminates in a tragic and violent conclusion, reflecting the consequences of Makoto's selfishness and the destructive nature of the relationships he fostered.

The main characters are defined by their emotional struggles and flawed decisions. Makoto Itou is portrayed as a passive and indecisive protagonist whose actions drive much of the conflict. Kotonoha Katsura evolves from a timid and loving girlfriend to a deeply troubled individual. Sekai Saionji, initially cheerful and supportive, becomes a tragic figure as her unrequited love and emotional pain consume her. Supporting characters, such as Hikari and Otome, add further complexity to the story, highlighting the ripple effects of Makoto's behavior.

"School Days" is notable for its exploration of themes like infidelity, emotional manipulation, and the consequences of poor decision-making. The series stands out for its dramatic and often unsettling portrayal of teenage relationships, culminating in a finale that leaves a lasting impact.