What is the symbol in Maris the Chojo's hair?

Question

From Maris the Chojo:

What is this symbol in her hair and what does it mean?

Answer 1

That's the currency symbol for the Yen, the Japanese currency.

The Wikipedia article you have linked to in your question has this to say:

Maris' obsession with money is demonstrated by her hair ornaments, in the shape of the symbol for Yen (Japanese money).