In Tokyo, Japan, a young girl named Ichigo Momomiya attends an endangered species exhibit with her "crush" Masaya Aoyama. After an earthquake, Ichigo and four other girls are bathed in a strange light. A cat appears before Ichigo, then merges with her. The next day, she begins acting like a cat and making cat puns. After meeting Ryou Shirogane and Keiichirou Akasaka, Ichigo learns that she was infused with the DNA of the Iriomote cat. Ryou and Keiichirou explain that this allows her to transform into Mew Ichigo, a powerful heroic cat girl. She is ordered to defeat Chimera Animas—alien parasites which infect animals and turn them into monsters. Ryou and Keiichirou instruct Ichigo to find the four other girls from the exhibit—the remaining Mew Mews.