If you don't know the story, well... Buckle in, this will take a sec. Ranma is a teenaged boy who sometimes turns into a girl. That's girl-type Ranma above left. (It's magic, something about falling into the cursed Pool of Drowned Girl.) Above right is Ryoga, Ranma's martial-arts rival, who was at the cursed springs at about the same time (tracking Ranma). Due to Ranma's rambunctious training exercises, Ryoga also fell into the cursed spring -- but in his case, the Pool of Drowned Piglet.
Anyway, the scene above is the critical moment in which Ranma learns that his fiancee's new pet piglet P-chan is actually his rival Ryoga -- and Ryoga learns that the idiot girl who caused him to fall into the spring is the same Ranma he was following all along. And he thought he hated Ranma before.
As any fan will confirm, I've left out a lot.
The first American publication of the manga was flopped horizontally, so that action flows from left to right to conform to left-to-right English. I've flopped it back and reversed the word balloons, so that the panel appears as originally drawn -- and more closely resembles the anime version of this same scene, as you can see.
Incidentally, there's absolutely no mention anywhere, in either medium, of the color of girl-Ranma's hair. No one ever acknowledges that it turns red. It probably wasn't supposed to: The animators did it to make her a more visually distinctive character.