The specified account (with/without withholding) vs the general account, tax reporting, and who should use each.
A specified account with withholding has the broker calculate and withhold tax so you usually need no return; without withholding the broker calculates but you file; a general account requires you to calculate everything yourself.
A taxable brokerage account in Japan comes in three forms. A specified account with withholding (特定口座・源泉徴収あり) has the broker calculate your gains and withhold the Japanese tax at source, so for those transactions a tax return is often unnecessary. A specified account without withholding calculates your annual results and gives you a report, but you normally file and pay yourself. A general account (一般口座) leaves you to calculate acquisition cost and taxable gain entirely.
All three are taxable (unlike NISA) and can be held alongside NISA and each other. The difference is purely how much tax administration the broker handles versus you.
For most people, the specified account with withholding is the simplest: the broker handles the tax, and you can often avoid filing for those trades entirely. The main downsides are that filing might still be useful (for example to claim loss offsets across brokers or foreign tax credits), and that declared income can, in some cases, affect social-insurance or dependent calculations.
A specified account without withholding suits those who prefer to manage their own filing and cash flow. A general account is needed only for assets or transactions the specified account cannot hold — it carries the highest recordkeeping burden and is rarely the default for ordinary investing.
Brokerage (NISA/iDeCo) · Rakuten Securities
A leading low-cost brokerage for NISA and index-fund investing, integrated with Rakuten points and Rakuten Bank.
Fees: Many domestic funds and trades are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · SBI Securities
Japan’s largest online brokerage by accounts, with a very broad low-cost fund lineup and full NISA/iDeCo support.
Fees: Many trades and funds are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · Monex
An established online brokerage often chosen for US-stock access and research tools, with NISA and iDeCo support.
Fees: Commissions vary by product; some funds/trades are low-cost — verify current schedule.
This is education, not a recommendation. Most beginners research low-cost, broadly diversified index funds — for example all-country (全世界株式) or S&P 500 trackers — rather than picking individual stocks, because low fees and diversification are within your control while returns are not. Understand that values fall as well as rise, match the risk to your time horizon, and never invest money you may need soon.