Relationships
Kyoka Jiro
Koji and Kyoka work together to pass their final exam.
Koji was partnered with Kyoka during the Final Exams Arc against Present Mic. Although Koji was very shy and terrified of insects, Kyoka's words and example of bravery convinced him to use his Quirk to talk to bugs of the forest. Koji carried an injured Kyoka through the forest to cross the escape gate and together they passed the exam.
Rikido Sato
As they sit next to one another, Koji and Rikido are often seen together and are partnered with each other during the Battle Trial Arc.
They both joined Team Hagakure during the Cavalry Battle in U.A. Sports Festival Arc.
Fumikage Tokoyami
Fumikage and Koji work together.
They fought the League of Villains together during the Unforeseen Simulation Joint Arc, so Koji is one of the people who knows Fumikage's weakness.
They also showed good cooperative skills with each other during the Provisional Hero License Exam.