[Heisuke]

I checked out the animated intro you mentioned, no ENF scene. The joke is one girl points the vacuum at the other (I can't tell them apart in the animation) and sucks her completely into her vacuum cleaner, then gets sucked up by it herself. I guess it's a joke about how thin the both are, or something. So it's safe to never watch this show again, which I plan to do from now on...