Kodama has to transfer schools a lot because of his father's work which is why he became Rutta's roommate in summer. Even though Rutta was a delinquent, he was never afraid of him and they slowly became friends. When Rutta confessed to him, he was confused but eventually accepted his feelings and they started dating. He also developed strong feelings for Rutta.
He does not waver much and despite seeming weak at first, he is able to stand strong and act boldly.
Wanting to become more muscular, he and Rutta started to work out every morning and evening.