Nearly 70% of companies listed on the top "prime" section of the Tokyo Stock Exchange have yet to respond to the bourse's call for better capital efficiency, a request that helped lift the Japanese market to 33-year highs.

The TSE made a rare call in March for firms to disclose plans in the long run to improve capital efficiency, especially if their shares are trading below book value, while setting no specific deadline to avoid companies making premature decisions.

The request, hailed by investors as a remedy to Japan's unusually high number of chronically undervalued stocks, led to a wave of share buybacks and dividend hikes, but results show a majority of firms have yet to come up with solid strategies.