Chrono Cross

Serge is a young boy from a fishermen's village. One day, while strolling on the sea shore with his sweetheart, Serge suddenly disappears. He comes back to senses several moments later. Everything seems just the same as it was before, but when Serge visits his home village, nobody recognizes him. He hears from people that he has been dead for ten years. Serge begins to realize that he is now in a parallel world. His first and only wish is to find a way to return home, but, in order to do that, he must understand what has caused the existence of parallel words, allowing inter-dimensional travel. His quest will also reveal to him the truth about his own existence.