Kudoh is Aki's classmate and also Misao's childhood friend. The two grew apart as they became older. Kudoh distanced himself from Misao due to the fact that his class mates made fun of him for hanging out with a girl, and that Yoshino was bullying Misao and that Kudoh didn't want to also be bullied, similar to Aki.

Kudoh is depicted as a 'calm and early-maturing youth' when he was first introduced in the opening cutscene in Aki's classroom. The creator of the game stated that Kudoh is supposed to be a contrast to Tohma's wild personality, so he is rather gloomy yet he has a strong moral compass (which is first displayed when Kudoh helped Misao when she was bullied as a child). However, he is rather cowardly due to the fact that he abandoned Misao so he wouldn't seem stupid in front of his friends in middle school. In high school, Kudoh is shown to be rational and much more mature than the others in his class. He is shown to be very empathetic (shown in his death cutscene where he talks about Misao to Aki) but he is rather hateful of others (especially if they're horrible to others) and self-deprecating also. He also doesn't say much unless it's required.