In Kimetsu no Yaiba, we see Tanjiro learning the water style from Urokodaki. But is it "magic" or just an artistic visualization?
It's never mentioned in the manga that this is some kind of magic, and it's made fairly clear that it's just a visualization that represents the user's style of swordsmanship (called breaths).
From the wiki:
The majority of known Breathing Styles mimic a certain element of nature (i.e. flame, water and wind) and replicates it with the user's movements, techniques and abilities.
When utilizing a Breathing Style, users automatically visualize themselves manipulating the subject behind their style, making it seem as if they were using magic, though those that are less apt and proficient in their style will visualize less than one who is.