Masumi Okuyama is a fourth-year student at Momogaoka College of Music who plays timpani and other percussion instruments. He comes from Yamagata and is known for his claustrophobia. Okuyama is an okama, possessing a male body but a feminine mind and demeanor. He develops an intense crush on Shinichi Chiaki, admiring him from afar, and initially says little to Chiaki until Megumi Noda, known as Nodame, enters their circle. Because Nodame begins spending time with Chiaki, Okuyama views her as a romantic rival and often bullies her or anyone else who tries to get close to Chiaki. Despite this rivalry, he becomes a close friend of Nodame and fellow student Ryutaro Mine. Okuyama’s personality is defined by his dramatic, jealous, and possessive tendencies, yet he is also fiercely loyal to those he considers friends. His primary motivation is his infatuation with Chiaki, which drives much of his comic and emotional behavior. Musically, Okuyama is exceptionally skilled, and his percussion abilities earn him the title Queen of Percussion. He is selected for the S Orchestra and later the Rising Star Orchestra, both conducted by Chiaki, showcasing his talent and earning him a respected place among the students. Throughout the story, Okuyama gradually becomes more comfortable interacting with Chiaki and the wider group, though his obsessive admiration never fully fades. His development is subtle, as he learns to channel his feelings into his music and forms genuine bonds beyond his initial crush. His notable abilities include technical mastery of percussion instruments, particularly timpani, and a strong sense of rhythmic precision that makes him a valuable ensemble player.