Heidi, Girl of the Alps c. 1974 : Space Battleship Yamato's rival for girls

Space Battleship Yamato signaled the beginnings of fandom as we know it, with teenagers turning up at the studio to show their enthusiasm. But the girls would sometimes admit they preferred Yamato’s rival: Heidi, Girl of the Alps. At the time, most TV anime were about sports or sci-fi, starring boys or beautiful women. Heidi, scheduled opposite Yamato and achieving identical ratings, highlighted the business case for TV anime targeting girls.

It also made the case for prestige TV animation. The penny-pinching conditions Osamu Tezuka accepted with Astro Boy’s undervaluation in 1962 had become the industry norm, but Heidi‘s director was Isao Takahata — previously demoted at Toei after ignoring deadlines and budget in pursuit of perfection on his debut feature, The Little Norse Prince (1968).

Heidi’s animators visited the Swiss Alps, shot reference footage, and used up to 8,000 cels per episode (Astro Boy’s average was 2,500, many reused). Impressive anime openings don’t typically represent a show’s animation, but this one does. Heidi’s quality, popularity, and exportability appealed to sponsors, who funded a string of “masterpiece anime” series based on children’s books. These were dubbed and aired around the world, popularizing this anime style.

Hayao Miyazaki (who danced around a car park with a colleague as a reference for Heidi and Peter’s dance in this sequence) described working on Heidi as “a year-long state of emergency,” which he realized was “the danger of television”: maintain that unsustainable state of emergency or sacrifice production quality. He chose to make movies instead.

https://www.vulture.com/article/most-influential-best-scenes-animation-history.html