The Cat Returns is a light, enjoyable, short film that is a sort-of spinoff to Whisper of the Heart.
The relationship between the two films:
One of the core elements of Whisper of the Heart is the main character of that film, Shizuku, writing a first, clumsy, novel called Whisper of the Heart. This novel used an intricate cat doll named Baron Humbert von Gikkingen as one of the two main characters .
The Cat Returns is effectively an anime adaptation of Shizuku’s first successful light novel; one where Shizuku is still using the Baron as a leading character but her female lead is now less of a self insert . Even the timing is roughly right if you assume that Shizuku kept writing through high school and now has 6 – 7 years of growth and maturity to draw on in her writing.
In which I actually talk about The Cat Returns:
The Cat Returns has a slightly odd character design style, a deliberate roughness somewhere between most Studio Ghibli films and My Neighbours the Yamadas . Although initially a bit disconcerting, this actually works well with the lead character Haru’s general lack of confidence.
The story itself is a light hearted mix of no good deed goes unpunished, being spirited away to a fairy cat kingdom, and needing to know who you are to go home again.
At about 70 minutes The Cat Returns is a short, tightly edited film that doesn’t overstay its welcome.
I think I agree with that assessment, and it’s certainly a film that I’d be happy watching every so often for light diversion.
 The other main character in this novel is a fairly obvious Self Insert of Shizuku, which is hardly surprising for a first novel by a teenager.
 I initially called this wild speculation unsupported by evidence. Now it’s wild speculation thinly supported by a claim on TV Tropes.
 The director of The Cat Returns, Hiroyuki Morita, was an animator on My Neighbours the Yamadas
- Twenty Days of Anime Movies – Day 14 – Whisper of the Heart (1995) (piratesobg.wordpress.com)