How long does it take to close a Japanese company?

At least 2 months, and typically 3–4. The shareholders resolve to dissolve, the dissolution is registered, and creditors get at least two months to submit claims through individual notices and the official gazette. After the assets are settled, completion of liquidation is registered. A company that cannot pay its debts needs a court procedure instead.

Company closure

Source: 1.7 Closure of branch offices or subsidiary companies, Japan External Trade Organization (JETRO)