Foreign issuers are required by the US Securities Exchange Act of 1934 (hereinafter the Exchange Act) to file with the SEC (the US Securities and Exchange Commission) an annual report, using Form 20-F, the registration and reporting form for foreign issuers.
(N.B.) “Issuers” ~ publicly-held companies are considered “issuers” under the Exchange Act, including companies whose American Depository Receipts (i.e., NIDEC) are listed on U.S. exchanges, such as NYSE.