All Nippon Airways has designated one lavatory for exclusive use by women on most international flights.
Men may use the women-only toilet only when there are few female passengers and in an emergency. Men can also use the ladies-only rest room before taking off and landing before the fasten-seatbelt sign is displayed, and when there is an urgent need due to illness. An announcement about a given flight’s toilet-usage is made at the start of the flight.
A 2007 ANA online survey found women do not like using unisex lavatories because men sometimes leave the seat up. Women also expressed displeasure about waiting in line for the toilet with men after airline meals.
ANA says 70% of male passengers it surveyed say they did not mind the ladies-only washrooms, and some men approved because it means less time waiting for women to finish using the toilet. ANA said demand for a lavatory exclusively for women is especially high among passengers taking long flights.