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



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