It’s more than anime, it’s where Miyazaki got his feet wet, before founding Ghibli. Same studio that co-produced Viky the Viking with German television. The whole thing is closely connected to Japanese romantisation of Europe as a place of nature and fairytales, very much pushed by Ghibli. In case you ever wondered why Frieren is full of German names and there’s christianish-looking priests and talk of heaven and tons and tons and tons of nature: It’s just continuing a tradition. And have a video about nature in anime in general and Ghibli in particular. While we’re at it have a long (and German) wikipedia article on Heidi in Japan