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
If you were in a religious household, or was babysat by the tv And watched CBN, you may have also seen Superbook and Flying House. Both stories about kids (time) traveling through biblical times. Both are anime and produced by Tatsunoko Productions.