Kōji Machida

Appearance
Kōji has brown hair and brown eyes. He is wearing his school uniform.

Plot
Kōji made his first appeared in Light Novel Volume 4 as a member of Class A assigned to the Rabbit Group along with Shigeru Takemoto and Takuro Morishige from his class. When Ichinose suggests the group to cooperate and clear the exam through the first outcome. Other students, including Kiyotaka, agree but Machida from Class A rejects the offer and instead proposes a strategy Katsuragi has come up with: to not talk at all until the exam is finished so that there won't be a traitor among the group and allow the points to be equally distributed among the classes. Ichinose argues the strategy is benefiting Class A the most since it would cause the position of the classes to be unchanged and help them keep the lead. However, Machida stubbornly refuses and says he and his classmates will continue staying silent and not take part in the group discussions.

When Manabe and her friends were persistently trying to take pictures of Kei to confirm their suspicions about Kei bullying Rika, Kei turns to Machida for help, who then tells Manabe to stop forcibly taking photos of Karuizawa and that it would be better to talk with Rika to confirm the story making Manabe withdraw. Similarly, when Kei asks to join Machida during their group meetings for the Cruise Ship Special Test, Machida agrees and assures to help her if anything happens.

Kōji later appears during Event Selection Exam where he is chosen to play in the Basketball event along with Shigeru Toba, Masumi Kamuro, Naoki Shimizu, and Hayato Kitō against Susumu Makida, Minami Setsuya, Kanji Ike, Ryōtarō Hondō, and Kayano Onodera from Class D.