An overview of hiking insurance providers in Japan.

Do you really need hiking insurance in Japan? Well, if you want to avoid paying $4000 USD for a helicopter rescue, then the answer is yes... "But is hiking really that dangerous? I probably won't need it" - this is both correct and incorrect. You don't need hiking insurance, and indeed I have hiked many mountains without insurance, and for easy hikes without technical terrain you can probably skip the insurance. But honestly speaking, this is not a wise decision. You cannot predict an accident, and the consequences of an accident far out-way it's low probability.
If you have a mild accident while walking down the street or driving a car, it's quite easy to get to hospital or simply get home to recover, but on the mountain these simple situations can become serious. If you trip on the pavement in the street, no worries, but if you trip on a rock on exposed terrain, then the fall can lead to significant injuries. Even simply rolling your ankle can result in a serious sprain that turns a 4 hour descent into an 10 hour ordeal which means you would have to spend the night on the mountain, and perhaps there's also a storm forecast later that evening. The next thing you know it's dark, the weather is bad, and you're freezing cold - hiking insurance solves most of these problems by covering you for helicopter rescues, plus the insurance itself is relatively cheap, usually around ¥4000 for an annual membership.
And the statistics on rescues is also pretty interesting. According to data from the Japanese government, there is an average of more than 2,000 mountain rescues each year, with helicopter rescues accounting for roughly 40% of these incidents. The most common reasons for rescues in Japan are:
Accidents and injuries
Getting lost
Adverse weather conditions
So here is an easy run-down of the best hiking insurance providers in Japan, you can sign up for these online using their websites.

Yamakifu - The Best Insurance For Short-Term Periods
Yamakifu is the only provider here that offers insurance for short periods, in case you only want it for the weekend. For Yamakifu, you must submit a hiking plan in order to be covered.
Price range: ¥660 - ¥4000
Period: 1-4 days or 1 year