Nagato on a riding machine. In swimwear, and bouncing somewhat. Also some Touhou and Hachune Miku riding a little differently below.
Maybe you’re getting tired of my enthusing all over the classic Yayoi Riding video, but I can’t really fail to mention it here.
Something a little different: a crossover of Idol Master, Touhou and Hachune, all very yukkuri.
Riding machine videos seem to have the perfect balance of ease of animation, music, and sufficient tameness to fit on video sites – the pinnacle of slightly H videos, perhaps? Did I mention Yayoi Riding?