I have to ask- why Eiken specifically for this? It seems just so out of left field since it is a 00's series. I'm not familiar enough with the vore community to really tell what makes good material.
Is it the jiggle physics? I could imagine it brings up images of slurp-able jello (see the gif for reference).
@dralemeres - Personally i love huge breasts, i came across the DVD in a store and got it because it had big anime titties on the cover. I admit the OVA isn't good, there are some good animation scenes and is very ecchi which got me to seek out the manga. The manga is "better", kind of a slice of life thing with huge busty women, pretty much a harem style school manga, but it had it's moments where it was more than tig o'l bitties.
I just like the designs and wanted more art of them since i like them.