Quite a bit of time has passed since I was at the Castle in Osaka. However, I remember walking around the vast compound and gardens and seeing the Shinto and Buddhist temples.
One thing that I remember well is the fortune strips, omikuji. This small piece of paper that people had left at the entrance of a temple. They were all folded in a simple knot. These knots helped keep the wishes people had left behind at the temple door. Keep it tight. They avoided that the wishes flew away, taken by the wind.