A young orphan, it was the death of his parents during a Gamilus planet bomb attack on the Miura Peninsula that drove him to follow in his older brother Mamoru’s footsteps and join the Earth Defence Force. He is initially hot-headed and prone to bursts of anger, and at first blames Captain Okita for the death of his brother in battle. However, he matures during the first season thanks to his responsibility as the Yamato ’s battle chief, and ultimately Okita nominates him acting captain when he is unable to continue. Though apparently never formally promoted to captain, Kodai continues commanding the Yamato and its crew for most of the rest of the franchise, only relinquishing command twice: to Yamanami in Be Forever Yamato, and to a revived Okita during Final Yamato. He is also a talented pilot, flying his own Cosmo Zero fighter as the leader of the Black Tigers, and in the second season frequently joining the Cosmo Tigers in battle.
His Japanese given name means “to go forward, to improve.”