I don't normally watch anime, but big studios like Gibli and directors like Hayao Miyazaki are the exception. A few songs from Yumi made to my playlist since then.
Joe Hisaishi's work in Miyazaki's movies are truly exceptional. If you like Yumi Arai's voice, maybe you'll like Ai Higuchi as well. Her style of music is different, but they have a similar tone.
Thank you for expanding my universe! I'll check out Ai Higuchi as well.
I don't know exactly what it is, it's not just the voice. 00:32 goes straight to the heart. Plus the childhood nostalgia, bitter-sweet feelings it's capable of bringing, the whole atmosphere. And I'm a sucker for falsettos, ie 01:13 in The Girl Is A Time Traveler. Same reason I like Fishmans. Imperfection somehow makes it perfect.