I saw it in 2004/5 so must have been released way earlier. It wasn't in the normal shoujo/shonen style drawing either.
All I remember is that there was a competition and the winner would inherit the forest. And people from evil compainies were buying/bribing the winners to win and give them the forest for industrial purposes.
Our protagonist is a girl and she is not interested but takes part anyway. There were some rather quirky moments which I remember such as:
During the competition there was a task where they had to take water out of a big bottle. A lot of them used a straw for this one.
The last round was between the protagonist and an intelligent girl with glasses and a laptop. The protagonist wins after deciding not to answer the question as answering the question correctly would have caused the glasses-girl to fall into the water.
Yep! That's it. Please help me! I really am not able to find this!