Before anything else head to the forest patch and fight there until you reach a mysterious ninja. Defeat her and follow the instructions.
1) Don’t ever use the save point or open your menu. If you do fight in the forest til you meet her again.
2) talk to her and answer “not interested”
3) talk to her again and answer “petrified”
4) then reply “wait a second”
5) reply “that’s right”
6) then reply “lets hurry on”