Tsuyoshi Nakanojou is a 15-year-old student in class 1-Q at Tokisadame High School. His defining physical trait is a natural yellow mohawk, caused by hair growing exclusively at the center of his head, a trait inherited from his father. This unique hairstyle stubbornly resists any attempt to style it normally, reverting to the mohawk. Once, teacher Kana Nakamura completely shaved his head during an incident involving Nano Shinonome, leaving him bald. His hair later regrew after Principal Shinonome accidentally applied a hair growth solution.

Despite his mohawk suggesting a delinquent, Tsuyoshi possesses a kind and gentle nature, often seen watering and caring for flowers. He uses respectful honorifics when addressing others. Aspiring to be a scientist, he maintains a strictly scientific worldview, rejecting beliefs in ghosts or spirits due to a lack of logical evidence. This skepticism motivates him to actively seek out and challenge individuals claiming supernatural abilities, like mediums, to disprove them.

He has experienced misunderstandings with peers: classmate Tanaka mistakenly believed Tsuyoshi was dating Haruna Annaka, and Tsuyoshi himself once misinterpreted a situation, thinking Annaka had sent him a love letter. He briefly earned admiration from Weboshii because of his mohawk, though this ended after his head was shaved.

Family tension exists with his father, who runs a rice cake stand and expects Tsuyoshi to inherit it. Tsuyoshi shows little interest in this future, actively avoiding related tasks such as promoting the stand in costumes. His scientific ambitions clash with his father's expectations.

Tsuyoshi frequently finds himself unwittingly swept into chaotic incidents, often suffering as collateral damage even when not the intended target of others' actions.