The Full Body Cat's Tongue Arc is the ninth story arc covered in the Ranma ½ manga, spanning nine chapters. It was included across volume 4 and 5 of the Viz Media publication and in volume 5 and 6 of the Weekly Shōnen Sunday publication.
Shortly after learning of Shampoo's return, Ranma meets her great-grandmother who tests Ranma's worthiness of becoming Shampoo's husband by using the Full Body Cat's Tongue on him, making even lukewarm water feel scolding (thus leaving Ranma unable to turn back into her male form).
Once Ranma narrowly beats Shampoo's childhood friend, Mousse, she begins working at the newly opened Cat Café in the hope of getting the Phoenix Pill from Shampoo's great-grandmother which can cure her from the Full Body Cat's Tongue. Although initially unsuccessful, Shampoo's great-grandmother decides to show Ranma the Katchu Tenshin Amaguriken; a technique she could use to take the Phoenix Pill from her.
Despite failing to get the real Phoenix Pill, Ranma follows Shampoo and her great-grandmother to a beach where they've set up business for the summer. There Ranma enters a race where the winner will get to date Shampoo (who currently holds the Phoenix Pill). However, once Ranma eliminates every other contestant, she begins fighting against Shampoo's great-grandmother as final test to prove her worthiness.
Massively outclassed, Ranma resorts to using the Nekoken to get the upper-hand and, although she still doesn't win, Shampoo's great-grandmother hands over the Pill for how much spirit Ranma showed during the fight; although she comments that she isn't done with Ranma yet...
- Shampoo opens the Cat Café with her great-grandmother.
- Mousse is revealed to be a childhood friend of Shampoo.