If asked to imagine a witch or magician from a fairy tale, many would probably imagine a broom as well. The regular magician Marisa loves her broom and uses it to fly.

This broom has the mysterious ability to make its rider feel like they are flying like a magician does. They can even use magic! ...Or at least, they feel like they could.

If you take this broom with you to Hakurei Shrine, the shrine maiden there might mistake it for a regular cleaning tool, even though brooms are essential items for magicians...

There are many magicians in Gensokyo, but not everyone has a broom. This is because those belonging to the species of magician do not actually need a broom.

Perhaps Marisa loves her broom so much because it brings her closer to the image she has of a magician. That would also explain her black outfit and hat, as well as how she always uses her broom to fly.