Japanese exchanges use a standard trading unit of 100 shares. A ¥4,000 quote therefore implies a ¥400,000 standard-lot purchase before fees.
Many brokers now provide access below one trading unit. Execution timing, eligible securities, pricing, fees and shareholder rights differ by provider.
A one-share holding may be a tracking position, the first step toward 100 shares or a budget-aware method of diversification. Share count alone does not reveal conviction.
For overseas readers, the useful first calculation is price per share × 100. Then ask how the position is being accumulated and what target weight it represents.
NISA can explain gradual, long-term accumulation by Japanese residents, but it is a tax wrapper—not an investment thesis. This guide keeps NISA secondary.