A nonchalant young woman who can feel no romantic emotions asks a hopeless romantic guy to teach her how to fall in love for the first time.

And fwiw this reminds me of Taming of the Shrew, except she doesn't ask for the guy's help, he's forced upon her by family. (Or modern take, 10 Things I Hate About You.)

If this is still seed of idea, how about this take:

?When a woman finds the perfect man, she desperately seeks to cure an illness ? her affliction to love caught after her mother's miserable marriages. So she enlists the help of a tutor, a guy that can't help falling in love.?

A bit wordy, but you get the idea

Along with what Richiev says...

That she doesn't feel romance is the issue so no need for nonchalant, which anyway feels off. Instead, paint more of the picture, as with her career or personal situation.

The lack of that emotion needs to be clearer so that we relate or empathize.? Is it a real or make-believe medical issue? Is it a matter of how she was raised?

What is the conflict when she recognizes the issue and gets help from an appropriate person?

Next attempt, see that any adjustments add up to a picture of the A Story. What actually happens most of the time?