Suzumiya Haruhi no Chokuretsu

Trouble comes to those who wishes for them and Haruhi is one who cannot live without some sort of havoc happening. One day, Kyon receives a strange message about the seven mysteries in school, and Haruhi being her usual self, would never let any sort of super natural events escape from her. So threatening all her club members with the death penalty, she forces all of them to go along with her summer adventure in school.

Talk to the various characters and reveal the secret behind the mysterious events, gather clues and work out the logical connection between them. You have to do all these before the strange forces that possess Haruhi do something strange with her powers.
[from Play-Asia]