These photos depict Guagua as a variety of characters and were originally uploaded earlier this year, but are now appearing on Japanese sites like Karapaia. The characters include Kiki from Kiki's Delivery Service and Naruto from, um, Naruto, among others.
The series of photos were taken to mark Guagua's birthday, apparently. So happy belated birthday!
The pics are cute, sure, but cat lovers might worry about the animal—as sticking one's head in a cardboard hole doesn't exactly sound "fun". Then again, neither does dressing up as Naruto.