A fourteen-year-old boy in the city where Kiki settles. He is obsessed with aviation, is a member of a club building a human-powered aircraft, and is at first intrigued only by Kiki's ability to fly. He later becomes her friend, although it is obvious that she awes him. (It is not clear, at least to an English-speaker, whether "Kopoli" is intended as a given name or family name. "Tombo", according to the novel, is a nickname, Japanese for "dragonfly".)
