According to PRESS RELEASE of Japan Patent Office, The operation concerning extension of the response period of the reasons for refusal in the patent application or trademark registration application has been changed.
Japan Patent Office

Source: Japan Patent Office Website

  1.  A two-month extension of the response period is permitted with one request without reasonable grounds.
  2.  A further one month extension of the response period is permitted with the second request without reasonable grounds.
Extension of the period up to three months is allowed.