One thing I'd consider, is instead of staying in Himeji overnight, take the train (40min on special rapid or you can also take shinkansen if you're fancy) to Kobe and stay there overnight. Get a hotel with a nice harbor view.

Himeji doesn't really offer a ton beyond the castle, Kobe is more tourist-friendly and has better restaurants / vibe. If your next destination is Kyoto it is along the way.