It hardly seems likely a kit called "Let's Write Our Will" would be a best-seller, but since its debut last year it has been a hit with elderly people.
Kazuo Nebashi, 73, from Tatsunomachi, Nagano Prefecture, became interested in writing a will three years ago when he was helping a woman in her 80s with inheritance problems.
The woman wanted to leave a legacy to her daughter-in-law after she passed away, but under the inheritance law she could not bequest anything to her without putting together a separate will.