Ichirō Yamada is a first-year student and a friend of the protagonist, Hajime Aono. He plays the cello and is known for his cheerful and energetic personality. Unlike the more reserved Hajime, Yamada is naturally outgoing and has little trouble making friends, often taking the initiative to strike up conversations with those who are more reluctant to socialize. His birthday is on April 5th.

Within the group of friends, which includes Hajime, Nao Saeki, Ritsuko Akine, and Haru Kozakura, Yamada often serves as a social catalyst and a source of levity, effectively acting as a lubricant for interpersonal relationships. He is a typical social butterfly whose friendly nature helps to balance and connect the various members of their circle. However, he does express frustration over the fact that as a cellist, he is frequently separated from the others during sectional rehearsals.

Yamada and Nao Saeki have known each other since middle school and have been close ever since. Having played the cello from a young age, Yamada was confident in his own abilities. This confidence was shattered after he heard Saeki play the violin. The encounter left him so disheartened that he considered giving up music entirely. At that low point, his father, who had previously been opposed to his musical pursuits, scolded him and declared that he would never allow his son to quit because of someone else's talent. This harsh but crucial advice prompted Yamada to change his mind and persevere with his instrument. This personal experience later proves to be impactful on Hajime Aono, who begins to re-evaluate his own approach to performing after hearing Yamada's story. As a character, his journey provides a key example of overcoming musical envy and finding the resolve to continue. His notable abilities lie in his skill as a cellist and his remarkable talent for fostering communication and building friendships within the orchestra.