Hikaru Kusakabe is an average teenager who enjoys his youth by smoking, going to parties, and playing in a band. His classmate Rihito Sajou, however, is the opposite of him; he's a top-performing student with a perfect score on his entrance exam. During a chorus festival rehearsal, Kusakabe notices that Sajou isn't singing and offers to help him practice. They start meeting every day after class to train, which leads them to develop feelings for each other despite their different personalities. As they approach the end of high school, students must make decisions about their future while learning more about themselves and supporting one another through this process.
Doukyuusei was published digitally in English as Classmates by Digital Manga Publishing on April 29, 2014, and in print as Classmates: Dou kyu sei by Seven Seas Entertainment on June 4, 2019; in Polish by Waneko and in Spanish by Tomodomo Ediciones on November 14, 2014.