4 HOT WAVE: mini album or single?

[Mad_Cactuar]

Objection! I was just thinking the other day and I don't think it's fair that 4 Hot Wave was classified as a single. Is it even a single? It's so much like a mini album. In fact, I believe it's indeed a mini album.

Because if it wasn't one, then Mika Nakashima's Oborodzukiyo Inori should also have been a single. And Resistance. Memorial Address has around the same amount of tracks with 4 Hot Wave too if you count the interludes.

4 A-sides on one CD? Isn't there some sort of format for CD single? I know western one's has a 20 minute limit if there's accompanying tracks or 40 (60?) if there's remixes chucked in. Isn't there a standard for Japanese singles?

Because if there aren't, Ayu might as well call her next mini album a maxi single.