I found this a few weeks ago, a rare sighting of someone other than ichigo with sprouting animal ears
It's from a little bonus comic Mia Ikumi did for the magazine "K-Dash"
featuring Pudding and Tart
She gets excited and her little monkey tail pops out (and wags even)
also, when Tart asks her where she learned to kiss like that she says something along the lines of "From watching Ryou and Keiichiro!"
((RyouxKeiichiro confirmed?))