It is a requirement for most nationals to have a Travel Health insurance for the whole duration of their time in Japan in order to get a Working Holiday Visa.

The following insurances are recommended:

• Travel Health Insurance (obligatory). This insurance will cover your expenses for medical consultation, treatments and prescription medicines. Also it usually pays for a flight back home, should it be necessary from a medical point of view, if confirmed by a doctor in Japan. As a Working Holiday traveller, staying for up to one year in Japan, you can also join the Japan National Health Insurance (国民健康保険 Kokumin-Kenkō-Hoken), but you don’t have to. You would need to pay for it an amount similar to foreign travel health insurances, but the Japan National Health Insurance only covers 70% of the medical costs, whereas foreign travel health insurances often cover 100%. As medical costs are relatively high in Japan, even the remaining 30% can make a substantial amount.
• Travel cancellation insurance. If you cannot travel to Japan after having made all travel arrangements due to a serious reason (e.g. serious illness, pregnancy etc – please check the conditions of the insurance), the travel cancellation insurance will reimburse your expenses. Travel cancellation insurances often need to be bought a certain time (e.g. one month) prior to your booked departure date.
• Liability insurance. As most companies in Japan have an employer’s liability insurance for their employees, this is often not necessary for those who are on a Working Holiday. In any  case, please make sure what such liability insurance covers. In some cases, travel liability insurances are limited to liability claims related to travel activities (e.g. if you cause damage to a hotel room, rental surf board etc.), and don’t include work-related liability claims.