Japanese patent law amendment as of April 1, 2012: the JPO permitted PCT applications to enter the national stage in Japan past the 30-month deadline.
As of April 1, 2012, the JPO created highly restrictive rules permitting PCT applications to enter the national stage in Japan past the 30-month deadline. If there is reasonable justification for the failure of the 30-month deadline, the JPO will accept the PCT application without an additional fee. In that case, within two months from the date that the justification no longer exists and also within one year from the 30-month deadline, it is necessary to file a Japanese translation of the PCT application and a written explanation of the justification. Then, the JPO will examine whether or not restoration will be allowed based on the written explanation.
This rule change is unlike the rule of unintentional failure in the USPTO and is more like the due care rule in the EPO; you can assume that the rule is similar to the EPO rule for restoring a PCT application when the deadline for filing a PCT national phase application is missed (EPC Act 122 & EPC rule 136).
It will be necessary to submit reasons for passing the 30-month deadline, the usual procedures of the agent for administration, documents to prove the reasons for the missed deadline, manuals that agent/client has, correspondence etc. The submitted documents will be published.
The definition of reasonable justification is as follows:
When the agent and/or applicant takes appropriate actions to enter the PCT national phase in Japan according to the circumstances, but the deadline is nevertheless missed, the JPO will deem that there is a reasonable justification for the failure.