[Matrixbeast]

A Kamen Rider episode with minimal action shoved in at the very end? I'm having flashbacks to Kuuga...

Well, not really, because, unlike Kuuga, things kinda happen.
Hibiki volume 3. It's basically all set up to a larger threat (That looks kind of giant, based on the shot at the very end).
So...This show is really quirky. Like, head tiltingly so. There are moments where this show feels Fourze level of quirk, like the SINGING. Seriously, what the hell? Why are they singing again? I don't know. There's also the fast pace gags that rear their head up as if Hibiki was predicting how KR would be acting a decade later. Oh well, they're not bad, mainly because they know how to space them so that it's not gag after gag.
So, not much really happened. There was nice set up with Asumu feeling weak and distracted while a large test reared it's head, all because he can't get Hibiki out of his head. It's an interesting concept. Hibiki himself is his easy going self, and...Yeah. This episode didn't really provide much and it was just build up towards the next.