There is no discovery process under the Japanese Code of Civil Procedure similar to that found in common law jurisdictions. It is usually quite difficult for a plaintiff to obtain evidence from a defendant or from third parties.

Whilst a procedure to obtain disclosure of specific documents exists, the document to be disclosed must be very precisely identified by the requesting party. The Code of Civil Procedure allows any party to demand that either the other party to the proceeding or a third party produce a document. The demand must clearly identify the requested document, its contents, the facts to be proven by the document and the legal basis for its production. Accordingly, disclosure of a wide number of unknown documents is not possible. Further, under the Code of Civil Procedure, a document that was created only for internal use may not be subject to discovery.

The demand is filed with the court, and, if accepted, the court will issue a corresponding order. The order may be appealed. If a party to the proceeding fails to produce a document in accordance with a court order, the court may deem the allegations made by the requesting party in respect of the requested document to have been proven. A third party who fails to comply with a court order requiring disclosure of a document may be sanctioned by way of a non-criminal fine not exceeding JPY 200,000. A party may also ask the court to subpoena a witness. Limited sanctions exist if the witness does not obey the court order.

Two other procedures may be used to obtain evidence prior to the commencement of proceedings. Firstly, the procedure of preservation of evidence allows a judge to confirm on-site the existence and contents of certain evidence. However, the judge may validly be refused entry to the premises where the evidence is held.

Secondly, lawyers are not allowed to directly demand the production of evidence prior to the commencement of proceedings but can do so through the bar association. However, the party being asked to produce the evidence may refuse to do so without risk of being sanctioned.