Character Arc
Kaoru Nishimi is the protagonist of Kids on the Slope, a quiet, top-of-the-class transfer student who arrives in Sasebo in 1966 carrying years of loneliness. Raised apart from his parents and moved repeatedly between relatives, he has learned to insulate himself from others, and the stress of starting over leaves him physically ill on his first day. A trained classical pianist, he initially looks down on jazz as chaotic and undisciplined.
His friendship with the rough-edged Sentaro Kawabuchi becomes the turning point of his story. Coaxed into playing jazz piano alongside Sentaro's drumming, Kaoru gradually loosens up, learning to improvise both at the keyboard and in his relationships. The music gives him a sense of belonging he has never had, and the basement record-shop sessions become the emotional center of his world.
Kaoru's arc is complicated by his feelings for Ritsuko Mukae, whose own heart leans toward Sentaro, creating a web of unrequited love that strains his closest bonds. Over the course of the series he is forced to confront jealousy, loss, and the impermanence that has defined his life, ultimately growing into someone capable of genuine connection rather than self-protective distance.