DE-JA

The name of this game's hero is Ryuusuke; he has a fascination for ancient civilizations and archeology, researching them thoroughly in hope of finding legendary treasure. One day he has a strange dream after having dozed off in his office: he has found an enormous mythical treasure, which is guarded by a terrifying monster... when he wakes up, he is contacted by an old man, who wants Ryuusuke to reveal the truth about a mysterious ancient staff.
And then strange things begin to happen...

[Edited from Moby Games]