Spend a rainy or hot day indoors
Most exhibits are indoors and a standard visit takes about one hour. Watch the puppet show and aerial footage in the theater (two screenings totaling about 35 minutes), explore the exhibits with a stethoscope, then rest in the second-floor lounge overlooking Senzu Station. This plan lets you spend your visit largely indoors. Add a sound-making workshop for another 30 minutes to an hour.
Parking → borrow a stethoscope at reception → Otogi Theater → museum exhibits → lounge.
The official site says some exhibits, Wind Walkway and Call Vision, are being adjusted because of equipment faults.