I know others have responded to this very well, but I do want to point out that what you like wearing very much has to do with gender presentation. The topic of gender is not as simple as "wears girl clothes, therefore girl" or vice versa, but it's also not as simple as "girl or boy". Gender is a complex network of interconnected topics including presentation, and exploration of that can mean something as simple as wearing clothes not associated with your gender or something more radical like wondering if you might identify more with a different gender entirely. On top of that, exploration is still exploration if you end up in the same place you started, so Haru wondering if she might be a boy is still exploration even if she decided she's still cis in the end.