School Days is a story about the relationships between three high school students: Makoto Itou, Kotonoha Katsura, and Sekai Saionji.
Makoto Itou is an average high school student who has a crush on his classmate Kotonoha Katsura. He takes the train to school every day with his friend Sekai Saionji, who helps him confess his feelings to Kotonoha. However, things don't go as planned and Makoto is soon caught in a love triangle between himself, Kotonoha, and Sekai. As the story progresses, Makoto's relationships with both girls become increasingly complex and strained as he struggles to choose one of them over the other. The consequences of his decisions have far-reaching effects that change all their lives forever.