Yoshiko is a bossy and irascible girl of 17 or 18 who lives in her parents' house in a dusty rural town in Japan. Her father is in hospital. She is called "gorilla-man" because of her resemblance to a manga character of the same name. The title refers to a handsome German lad who also lives in the town. His presence is explained part-way through, but the explanation is not convincing. Yoshiko starts teaching the recorder to young children, has various little adventures with them, and pursues her dream of becoming a famous singer.
This felt rather like an amateur film. The budget was obviously very low, the image is 4x3 or so (not widescreen), and it is only 70 minutes long. Most of the actors are children. Some of the acting is distinctly wooden. Eventually, the film tails off into wordless and abstract scenes where nothing happens. But it is frequently funny and occasionally surprising. You could say it is a fresh and original film.
The English subtitles were far from perfect. There were spelling mistakes, and on at least one occasion they did not even try to translate a word - they just said "this photo will be bokeh", or something like that.
Warning: there are many casual mentions of extremely unpleasant topics, and one or two scenes that actually show people doing very unpleasant things. These are things that you would definitely not want young children to see or hear.