https://www3.nhk.or.jp/news/html/20230829/k10014177831000.html
On August 29th the ministry of justice presented their draft of the amendment to the civil code to allow for joint custody.
As of now, it is only confirmed that in the case of mutual divorce, joint custody will be an option that both parents can agree to.
As for cases where custody is highly disputed between the parents, the courts would make the decision whether or who to grant sole custody to or to grant joint custody based on the best interests of the child.
This unfortunately doesn’t confirm the “gensoku joint custody” principle (where joint custody is the default custodial arrangement and sole custody is only approved for cases of DV) that proponents were hoping for.
From this point on, the draft will be sent to the legislative sub committee where they will go through several rounds of debate. It is still uncertain but there may not be any more big changes or they risk having the amendment delayed.
If all goes well, the legislative subcommittee will approve the joint custody plan by the end of the year and the MOJ will then create the formal amendment to be sent to the National Diet where the lower and upper house will vote on its implementation.