S1·E28 Kitty Panic! The Key to the Mystery is Her Kiss

As a cat, Ichigo gets lost while trying to escape from a large amorous cat. She finds herself standing in front of Masaya's house, where he discovers her and takes her inside. That night while he's asleep, she decides to kiss him, but accidentally kisses his dog instead. The kiss turns her back into a human, but before she can escape out a window, the dog licks her and she changes back into a cat again. Outside the house, the large cat finds her again, but she is rescued by a small grey cat wearing a green bandanna. Ichigo falls into the river, but the cat saves her again and tells her his name is Alto before she loses consciousness. She wakes up back on land and in her human form with Ryou bending over her and Alto gone. Ryou tells her that she must defeat the aliens as soon as possible if she wants to stop turning into a cat. While taking her home, he apologizes to her though does not say why.