First, win the battle with Kane. Then, return to Rudo. On the right corner of the building with the hanging shirts should be a parchment which reads "Fluttering". Enter the building where you previously woke up. On the opposite wall are five white parchments. Read the fourth one from the left. It says "White". While going out of the city, stick to the left wall and try not enter battle. Keep going left, and when you can go no more in that direction, go down. There will be a board which reads "The boy...". Return to the city without entering a battle. Go to the building with the shirts. There will be three lines of shirts. Look for the line with only one shirt and search it. It will say "Search the statue". Search the statue of the dragon god. Musashi will join you after a short talk.