Should rewatch (and reread) YKK one of these days, both are great and I think about the sort of mono no aware-related themes presented in them every now and then. Maybe it's a bit harder for me to separate YKK and Aria in my head because of the mentioned Choro Club OST overlap and the watercolor sort of look they both take on at times.... Although the post mentions layers with respect to Quiet Country Cafe, that actually brings to mind some of the bits of the first OVA series that I found the most memorable in ::: spoiler YKK first OVA series the insert song bits that layer Alpha on top of various post-apocalyptic Yokohama scenery. :::