On the shelf: a CardCaptor Sakura wand, plush toys of Greg Dean of Real Life Comics, Ralph of Exploitation Now, and Christian of Little Gamers.
Piro's hasty disguise is a Puchiko hat and Dijiko gloves, both of DiGi Charat. Which matches his shirt nicely.
Puchiko adds "nyu" to the end of her sentences, hense the "nyu" in the strip title.
Piro's rant below strip  briefly explains DiGi Charat.
Erika's dress and ears are from the Kanon character Kawasumi Mai.