Over the past decade, the importance of financial performance evaluation has grown substantially amid intensifying competition in global markets. Among the key indicators of corporate performance, Basic Earnings per Share (EPS) remains one of the most significant measures of shareholder profitability. EPS indicates the amount of net income attributable to each outstanding common share and serves as a fundamental benchmark of financial stability, operational efficiency, and investment attractiveness. Financial ratios such as Gross Margin, Pre-tax Profit Margin, Return on Assets (ROA), and Long-term Debt to Capital Ratio are widely used to assess a company’s financial condition and investment potential. These indicators capture essential aspects of profitability, efficiency, and capital structure, and may also function as determinants of shareholder returns reflected through EPS. Understanding the extent to which these financial metrics influence EPS is crucial for both theoretical development and practical financial decision-making. The Japanese automotive industry, known for its advanced technological capabilities, strong export orientation, and highly competitive global position, offers a particularly relevant context for such analysis. Nevertheless, financial performance volatility within the sector may significantly affect shareholder returns. Identifying the most influential financial drivers of Basic EPS is therefore of considerable importance. This study aims to evaluate the impact of selected financial ratios on Basic EPS, determine the strength and direction of their relationships, and analyze their contribution to shareholder profitability in Japanese automotive companies. The research contributes by proposing a structured analytical framework for examining the linkage between financial indicators and Basic EPS, providing valuable insights for investors, financial analysts, and corporate managers.