I've visited twice, first visit was 1.5hr, second visit 4.5 hours (not even joking the slightest bit). What totally confused me was the 2nd visit queue wasn't much longer than the 1st visit. The only reason I can think of was it was April i.e. Sakura i.e. peak tourist season and so the diners were full of tourists extending the dining time by 2 minutes each piece for photos