The whole opening for episode 12. The whole thing. Kyoko turning and speed-walking from Ren and his "super gentlemanly smile" (not to mention his Bishie Sparkle). Ren cornering her before she can duck into the ladies' room and proceeding to school her on manners. The encounter being underscored by a grinning cartoon lion pouncing after a bunny that's on the run.
Kyoko grabbing up her little angel selves and slamming them into Sho's face in the first chapter. Hysterical on every reread of the manga.