In Japan if you go through the trouble to buy that basket of stock in the index (well, before futures and etf are invented I suppose), you actually get many shareholder benefits which is sort of monetary reward program for owning the stock. Which can yield about 1% on top of dividends.
https://asia.nikkei.com/Markets/Tokyo-Market/Japan-s-companies-embrace-gift-giving-to-lure-investors
For example, a chain store Bic camara (stock number 3048) would send 1000 yen coupons to the stock owners.
http://www.biccamera.co.jp/ir/service/index.html
owning 1000 stock cost JP¥1,421,000
The company send you 10x 1000yen coupons in a year for owning 1000 stock. If you hold the stock for more than 2 years, you get 2x 1000 yen coupon each year.
So you would get ¥12000 yen coupon to spend with an investment of JP¥1,421,000
If you want to squeeze out every bit of juice, you can buy 100 stock instead and they would still send you 3 coupon each year + 2 for holding it long term.
There are Japanese web sites teaching people how to live off these programs.
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Calculation assume no dividend, so dividend saved up over these working years can be used to help funding living expenses. You also get dividend which is about 1% in the early day and near 2% recently.
If you work in Japan you are also forced to join this.
http://www.nenkin.go.jp/international/english/nationalpension/nationalpension.html
which pay ¥779,300/ year (full benefit amount based on 40 years of fully contributed coverage periods)
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Yeah 30% is aggressive, I should have use something like 15%, so just cut the figure into half and adding that to the Japan pension plan.