The article estimates the cost of capital for Japanese property insurance companies by analyzing their equity beta. They use different models to calculate the overall equity beta and cost of capital for each company, as well as for specific business lines. The study shows that the Capital Asset Pricing Model and Fama-French Model are effective in estimating equity beta and cost of capital for these companies. Additionally, the Full-Information Industry Beta methodology reveals that the equity beta varies across different business lines within the companies.