The story takes place in the 1970s on the island of Belitung, Indonesia, where the protagonist, Ibi, a young teacher, is assigned to teach a group of students from different backgrounds and economic statuses. Despite the challenges they face, Ibi and her students work together to create a better learning environment and eventually establish a makeshift school, which they call the "Rainbow School". Through their collective efforts, they strive to overcome the obstacles and limitations imposed by their socio-economic circumstances.