Temple of Ranma's Sailor Senshi Seifuku

It's just one of those mysteries left open for interpretation. So... Interpret away. ^^

My personal opinion is a mixture of two and three, with maybe a trace of some other reasons too. Kasumi is a fairly bright girl, if rather sheltered, and while doing housework would eat up most of her time, she would have some time to herself- and cleaning and cooking don't exactly give your brain much to do. Medical knowledge is very study extensive and it comes in handy in a house with someone like Akane- and probably more so after Ranma and his father move in (though I admit that I believe Ranma and Genma take care of most of Ranma's wounds). In fact, she might even have had ambitions of becoming a nurse or a doctor before she had to start running the house.

Personally, I don't think she would have been using it as a ploy to attract Tofu's attention. Outside of the "Red Shoe Sunday" ending theme for the last half-dozen OAVs, she's never given any sign of being interested in him. And given that he goes into hysterics at the mere mention of her name, coupled with her own naivety, I doubt she would even be aware of his attraction to her. Besides which, someone as responsible and dutiful as Kasumi probably wouldn't be attracted to an apparent goofball like Tofu anyway- her distaste for younger men in the first episode/volume likely stems from her belief that such a "candidate" would be terribly immature.

Since Kasumi doesn't show medical skills or shiatsu techniques at any point later in the series to my knowledge, I'll assume it was a pointless plot device in order to give Tofu a comedic quirk and prevent him from becoming a useful role model to Ranma that would make the plot more serious, as well as instill silliness in more main characters. Kasumi simply provided a foil to make Tofu loony in that arc, and later on, likely the only reason she didn't disappear from the story like Tofu did was because she was one of the Tendo sisters.

Nekomata-sensei wrote:Since Kasumi doesn't show medical skills or shiatsu techniques at any point later in the series to my knowledge, I'll assume it was a pointless plot device in order to give Tofu a comedic quirk and prevent him from becoming a useful role model to Ranma that would make the plot more serious, as well as instill silliness in more main characters. Kasumi simply provided a foil to make Tofu loony in that arc, and later on, likely the only reason she didn't disappear from the story like Tofu did was because she was one of the Tendo sisters.

What he said. That's my opinion too.